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Imatinib resistance is a major obstacle to the successful treatment of gastrointestinal stromal tumors (GIST). Long non-coding RNAs (LncRNAs) have been identified as important regulatory factors in chemotherapy resistance. This study aimed to identify key lncRNAs involved in imatinib resistance of GISTs. First, MSC-AS1 was found to be upregulated in imatinib-resistant GIST tissues and imatinib-resistant GIST cells. Cellular experiments demonstrated that MSC-AS1 overexpression decreased imatinib sensitivity of GIST cells, evidenced by increased cell survival, colony formation, migration, and invasion. Moreover, suppression of MSC-AS1 improved the imatinib resistance of imatinib-resistant GIST cells. Furthermore, MSC-AS1 upregulated the expression of FNDC1 and Anillin via sponging miR-200b-3p, activated the phosphatidylinositol-3-kinase-AKT signaling pathway, and thereby driving imatinib resistance in vitro and in vivo. Overall, this study elucidates the crucial role and mechanism of MSC-AS1 in the imatinib resistance of GIST, providing the potential therapeutic strategy for overcoming the imatinib resistance of GIST., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests. Ethical approval: All clinical experiments were approved by the Ethics Committee at China-Japan Union Hospital of Jilin University (2023-KYYS-023) and operated following the Declaration of Helsinki. Informed consent: Informed consent was obtained from all participants. Human or animal rights: All animal experiments were conducted in accordance with institutional guidelines and were approved by the Institutional Animal Care and Use Committee of Yishengyuan Gene Technology Co., LTD (No. 20240107)., (© 2025. The Author(s) under exclusive licence to Japan Human Cell Society.)

Background/aim: Gastrointestinal stromal tumors (GISTs) are rare cancers originating from Cajal's stromal cells in the gastrointestinal tract. The most common driver mutation in these cancers is the KIT mutation. This report presents a case of response to low-dose imatinib in a patient with GIST harboring KIT exon 11 W557_K558 deletion., Case Report: In June 2023, an 82-year-old male developed perineal pain. Computed tomography (CT) imaging revealed a mass measuring >9 cm, extending from the rectum to the prostate. Submucosal tumor biopsy revealed a tumor with CD117-positive and DOG1-positive spindle-shaped cells leading to a diagnosis of GIST. c-Kit gene mutation analysis detected a W557_K558 deletion in exon 11. Treatment with imatinib (400 mg/day) was initiated in late October 2023 to preserve organ function; the dose was reduced to 300 mg/day after 5 days of treatment and further reduced to 200 mg/day after 10 days, with continued treatment at this dose. The CT performed in January, April, and June 2024 showed that the rectal GIST had shrunk. The blood imatinib concentration remained at approximately 650 ng/ml from January to March 2024 and decreased to 391 ng/ml in May 2024., Conclusion: The response rate of GISTs to imatinib is influenced by genetic mutations. GIST with KIT exon 11 W557_K558 deletion is associated with a high risk of recurrence. In vitro data showed that low-dose imatinib was effective in such cases. Low-dose imatinib is a treatment option for patients with GIST harboring KIT exon 11 W557_K558 deletion who are intolerant to high-dose imatinib., (Copyright © 2025, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Introduction: In addition to mutations in KIT and PDGFRA, many other genetic alterations have been described in gastrointestinal stromal tumors (GISTs), including amplifications of C-MYC and EGFR, which are often associated with increased protein expression. The main of this study was to investigate the prognostic significance of C-MYC and EGFR expression in GISTs using immunohistochemistry (IHC)., Methods: We collected all GIST cases over a 16-year period. These cases were tested using antibodies against C-MYC (Leica, clone EP121) and EGFR (Leica, clone 113). C-MYC staining was assessed using the H-score method for nuclear, cytoplasmic, and combined staining. For EGFR staining (either cytoplasmic or nuclear), the intensity was graded as follows: 0 (no staining), 1 (weak staining), 2 (moderate staining), and 3 (strong staining). The percentage of positive cells was evaluated using a semiquantitative approach. Statistical analysis was performed using SPSS24., Results: A total of 37 cases were included in our study. Nuclear expression of C-MYC was observed in 43% of the cases, with a high H-score in 43%. A statistically significant association was found between a high nuclear H-score for C-MYC and mitotic rate (P=0.046), as well as a high Ki-67 proliferation rate (P=0.046). However, no statistically significant associations were identified between the nuclear H-score of C-MYC and other clinical, pathologic, or survival data. Cytoplasmic expression of C-MYC was noted in 22% of cases, but no significant correlations were found with the clinicopathological data. EGFR staining was observed in 86% of cases, with a high score of 51%. EGFR expression was significantly associated with the mitotic index (P=0.012) and Ki-67 proliferation rate (P=0.046)., Conclusions: Our findings suggest that both C-MYC and EGFR may be overexpressed and/or amplified in GISTs, indicating their potential prognostic role. This could also pave the way for therapeutic strategies targeting these proteins., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Gastrointestinal mesenchymal tumors (GIMTs) are being increasingly resected under endoscopy. Large GIMTs cannot be completely retrieved through the mouth, but the cut-off diameter of peroral en bloc retrieval (PEBR) for GIMTs completely resected is still unknown. This study aimed to investigate the ability of maximum transverse diameter (MTD) to predict the PEBR rate of GIMTs after endoscopic resection (ER)., Methods: We retrospectively reviewed all patients who underwent ER for upper GIMTs from January 2009 to August 2023. The MTD was measured according to the maximum transverse diameter of specimen immediately retrieved after ER. For the PEBR rate, the independent predictors and optimal cut-off value of MTD were determined by logistic regression analysis and the receiver operating characteristic (ROC) curve analysis. The potential significance of preoperative CT for the evaluation of MTD was also clarified., Results: A total of 2032 patients were diagnosed with upper GIMTs after en bloc resection under endoscopy. The overall PEBR rate was 98.72% (2006/2032). The PEBR rate was 100% for 1943 GIMTs with MTD < 2.5 cm, 85.71% (60/70) for GIMTs with 2.5 cm but ≤ 3.0 cm, and 15.79% (3/19) for GIMTs with MTD > 3.0 cm, and these rates were significantly different (P < 0.01). In terms of the PEBR rate of GIMTs, the ROC curve revealed that the optimal cut-off MTD value was 3.0 cm, and logistic regression analysis revealed that MTD > 3.0 cm was an independent predictive factor (OR 71.07, 95% CI 9.14-552.43; P < 0.001). The MTD of CT was related to that of the resected specimen (r = 0.7149, P < 0.01), and CT underestimated the mean MTD of upper GIMTs by 0.17 cm (95% CI 0.09-0.24, P < 0.01)., Conclusion: MTD is an effective indicator for predicting the PEBR rate of GIMTs after ER. Resected specimens with MTD > 3.0 cm could not be routinely retrieved en bloc. Preoperative CT is suitable for evaluating the MTD of GIMTs, but underestimates the mean MTD of upper GIMTs by 0.17 cm., Competing Interests: Declarations. Disclosures: Xiuxue Feng, Ying Gao, Fei Gao, Huikai Li and Enqiang Linghu have no conflict of interests or financial ties to disclose., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Gastrointestinal stromal tumors (GISTs) have malignant potential, and treatment varies according to risk. However, no specific protocols exist for preoperative assessment of the malignant potential of gastric GISTs (gGISTs). This study aimed to use machine learning (ML) to develop and validate clinically relevant preoperative models to predict the malignant potential of gGISTs., Methods: This study screened patients diagnosed with gGISTs at the Affiliated Hospital of North Sichuan Medical College. Moreover, this study employed the Least Absolute Shrinkage and Selection Operator (LASSO) and logistic regression to identify risk factors. Subsequently, an ensemble of ML models was used to determine the optimal classifier. In addition, this study used SHapley Additive exPlanations (SHAP) for tailored risk profiling., Results: This study included 318 patients with gGISTs. Using LASSO regression and multifactorial logistic regression, this study analyzed the training dataset, revealing that the presence of endoscopic ultrasound (EUS) high-risk features, tumor border clarity, tumor diameter, and monocyte-to-lymphocyte ratio (MLR) were significant predictors of high malignancy risk in gGIST. As determined by our ML approach, the logistic classification model demonstrated optimal performance, with area under the receiver operating characteristic curves of 0.919 for the training set and 0.925 for the test set. Furthermore, decision curve analysis confirmed the clinical relevance of the model., Conclusion: High-risk EUS features, ill-defined tumor margins, larger tumor diameters, and elevated MLR independently predicted increased malignant potential in gGIST. This study developed logistic regression models based on these factors, which were further interpreted using the SHAP methodology. This analytical approach facilitated personalized therapeutic decision-making among diverse patient populations., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: British Sarcoma Group guidelines for the management of GIST were initially informed by those published by the European Society of Clinical Oncology. This update was written by a group of experts to includes a discussion of the highlight improvements in our knowledge of the disease and recent treatment developments. The guidelines include sections on Incidence, Aetiology, Diagnosis, including risk assessment, Treatment and Follow-up., Methods: A careful review of the literature was performed to ensure that wherever possible recommendations are supported by the results of clinical trials or substantive retrospective reports. Areas of uncertainty are indicated appropriately., Conclusion: Guidelines represent a consensus view of current best clinical practice. Where appropriate, key recommendations are given and the levels of evidence and strength of recommendation gradings are those used by the European Society for Medical Oncology (ESMO)., Competing Interests: Competing interests: The following authors reported no competing interests: IJ, MA, NW. The following received honoraria from Deciphera for attendance at advisory boards etc: MS, PD, RB and RJ. RB also received honoraria from Blueprint. RJ also reports receipt of grants from MSD and GSK and consultation fees from Adaptimmune, Astex, Athenex, Bayer, Boehringer Ingelheim, Blueprint, Clinigen, Eisai, Epizyme, Daichii, Immunedesign, Immunicum, Karma Oncology, Lilly, Merck, Mundipharma, Pharmamar, Springworks, SynOx, Tracon, UptoDate., (© 2024. The Author(s).)

Purpose: This study aims to define the computed tomography (CT) criteria that distinguish extra-gastrointestinal stromal tumors (eGISTs) from intra-abdominal fibromatosis (IAF)., Methods: Retrospective analysis was conducted on CT images obtained from 31 pathologically confirmed cases, including 17 cases of eGISTs and 14 of IAF. Various parameters [e.g., lesion location, contour characteristics, border delineation, enhancement patterns, presence of intralesional necrosis, vessels, air, fat, and hemorrhage, the long diameter (LD), LD/short diameter (SD) ratio, and volume (LD × SD × height diameter)] were meticulously evaluated. In addition, the degree of enhancement during arterial and portal venous phases and the lesion-to-aorta CT attenuation ratio during both phases were quantified. Statistical analysis was performed using Fisher's exact test, the Student's t-test, and the receiver operating characteristic curve to identify significant CT criteria. Sensitivity and specificity assessments were conducted for single and combined CT criteria., Results: Significant differentiators between eGISTs and IAF include non-mesenteric localization, irregular contour, well-defined borders, heterogeneous enhancement, presence of intralesional necrosis and vessels, and absence of intralesional fat, with LD exceeding 9.6 cm, an LD/SD ratio >1.22, and volume surpassing 603.3 cm 3 ( P < 0.05). A combination of seven or more of these criteria yielded a specificity of 100%., Conclusion: Ten distinct CT criteria have been identified to distinguish eGISTs from IAF, notably encompassing non-mesenteric localization, irregular contour, well-defined borders, heterogeneous enhancement, presence of intralesional necrosis and vessels, absence of intralesional fat, LD >9.6 cm, an LD/SD ratio >1.22, and volume surpassing 603.3 cm 3 ., Clinical Significance: The current findings establish CT criteria to distinguish eGISTs from IAF in a clinical setting., Competing Interests: The authors declared no conflicts of interest.

The rectovaginal septum is a rare location for gastrointestinal stromal tumors (GIST) to occur. The aim of this study was to present a case of synchronous local recurrence of solitary liver metastasis originating from an extra gastrointestinal tumor (E-GIST) of the rectovaginal space., (This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Purpose: To assess and compare the diagnostic efficiency of histogram analysis of monochromatic and iodine images derived from spectral CT in predicting Ki-67 expression in gastric gastrointestinal stromal tumors (gGIST)., Methods: Sixty-five patients with gGIST who underwent spectral CT were divided into a low-level Ki-67 expression group (LEG, Ki-67 < 10%, n = 33) and a high-level Ki-67 expression group (HEG, Ki-67 ≥ 10%, n = 32). Conventional CT features were extracted and compared. Histogram parameters were extracted from monochromatic and iodine images, respectively. The diagnostic efficiency of the histogram parameters from monochromatic and iodine images was assessed and compared between the two groups. Spearman's correlation analysis was used to correlate histogram parameters with Ki-67 expression., Results: The HEG was more likely to present with an irregular shape and a larger size than the LEG (all p < 0.05). Regarding histogram parameters, the HEG showed higher maximum, mean, Perc.10, Perc.25, Perc.50, Perc.75, Perc.90, Perc.99, SD, variance, and CV of monochromatic images; higher maximum, Perc.99, and entropy of iodine images, compared with the LEG (all p < 0.003125). ROC analysis showed that significant histogram parameters of monochromatic and iodine images allowed for effective differentiation between LEG and HEG. DeLong's test showed that the diagnostic efficiency of histogram parameters in monochromatic images (Perc.90) was superior to that of iodine images (maximum) (p = 0.010). A positive correlation was observed between the significant histogram parameters and Ki-67 expression (all p < 0.05)., Conclusion: Both histogram analysis of monochromatic and iodine images derived from spectral CT can predict Ki-67 expression in gGIST, and the diagnostic efficacy of monochromatic images is superior to iodine images., Competing Interests: Declarations. Ethics approval and consent to participate: Ethical approval (2020 A-070) was obtained from the ethics review board of Lanzhou University Second Hospital; the requirement for informed consent was waived owing to the retrospective nature of the study. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: Gastrointestinal subepithelial lesions (SELs) range from benign to malignant. Endoscopic ultrasound (EUS)-guided fine-needle biopsy (EUS-FNB) is used widely for pathological diagnosis of SELs. Early diagnosis and treatment are important because all Gastrointestinal stromal tumors (GISTs) have some degree of malignant potential. Diagnosing SELs with EUS-FNB is more difficult than diagnosing other tumors because an accurate diagnosis of GIST requires a sufficient tissue sample for immunostaining, which is part of the diagnostic protocol. Moreover, EUS-FNB is less accurate for diagnosis based on samples from SELs measuring ≤ 2 cm. However, our retrospective study showed that more than 50% of patients with SELs ≤ 2 cm were diagnosed as GIST. Therefore, EUS-FNB needles are required with adequate sampling in SELs measuring ≤ 2 cm. Previously, we conducted a retrospective single-center study of SELs measuring ≤ 2 cm, and reported that EUS-FNB with a Fork-tip needle was superior to that with a Franseen needle in that the former acquires sufficient sample. This multicenter comparative open-label superiority study is designed to verify whether a 22G Fork-tip needle is superior to a 22G Franseen needle with respect to sample acquisition., Methods/design: Present study will randomly assign for 110 patients (55 in the Fork-tip needle group and 55 in the Franseen needle group) with SELs measuring ≤ 2 cm, all of whom are managed at one of the 10 participating endoscopic centers. The primary endpoint evaluates the superiority of a 22G Fork-tip needle over a 22G Franseen needle for collection of an adequate tissue specimen at the first puncture. The secondary endpoints compare successful puncture rate, procedure completion rate, number of adverse events, diagnostic suitability of the first puncture specimen for GIST, and the number of punctures required until adequate specimen collection., Discussion: The outcomes may provide insight into the optimal needle choice for diagnosis of SELs ≤ 2 cm, thereby aiding development of practice guidelines. Present study is expected to promote early definitive diagnosis of GISTs, thereby increasing the number of cases that can receive curative treatment and improving prognosis., Trial Registration: Japan Registry of Clinical Trials (JRCT; trial registration: jRCTs052230144). Registered December 13, 2023. (URL; https://jrct.niph.go.jp/re/reports/detail/76858 )., Competing Interests: Declarations. Ethics approval and consent to participate: This protocol has been approved by Wakayama medical University Certified Review Board (approval number. W-59). The results will be submitted to peer-reviewed journals and will be presented at international conferences. Informed consent will be obtained from all patients by investigator. Consent for publication: Not applicable. Competing interests: The authors declare that they have no competing interests., (© 2024. The Author(s).)

Background: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Recent advent of tyrosine kinase inhibitors (TKIs) has significantly improved the prognosis of GIST patients. However, responses to TKI therapy can vary depending on the specific gene mutation. D842V, which is the most common mutation in platelet-derived growth factor receptor alpha exon 18, shows no response to imatinib and sunitinib. Radiomics features based on venous-phase contrast-enhanced computed tomography (CECT) have shown potential in non-invasive prediction of GIST genotypes. This study sought to determine whether radiomics features could help distinguish GISTs with D842V mutations., Methods: A total of 872 pathologically confirmed GIST patients with CECT data available from three independent centers were included and divided into the training cohort ( n = 487 ) and the external validation cohort ( n = 385 ). Clinical features including age, sex, tumor size and location were collected. Radiomics features on the largest axial image of venous-phase CECT were analyzed and a total of two radiomics features were selected after feature selection. Random forest models trained on non-radiomics features only (the non-radiomics model) and on both non-radiomics and radiomics features (the combined model) were compared., Results: The combined model showed better average precision (0.250 vs. 0.102, p = 0.039) and F1 score (0.253 vs. 0.155, p = 0.012) than the non-radiomics model. There was no significant difference in ROC-AUC (0.728 vs. 0.737, p = 0.836) and geometric mean (0.737 vs. 0.681, p = 0.352)., Conclusions: This study demonstrated the potential of radiomics features based on venous-phase CECT images to identify D842V mutation in GISTs. Our model may provide an alternative approach to guide TKI therapy for patients inaccessible to sequence variant testing, potentially improving treatment outcomes for GIST patients especially in resource-limited settings., Competing Interests: Declarations. Ethics approval and consent to participate: The institutional review board approved the study protocol, and the study was conducted in accordance with ethical principles of the 1975 Declaration of Helsinki and subsequent revisions (KY2023-002-B). Consent requirement have been waived by institutional review board due to its retrospective study. Consent for publication: Not applicable. Competing interests: The Author (Yang Song) from a commercial company, Siemens Healthineers Ltd., was a MR collaboration scientist doing technical support in this study under Siemens collaboration regulation without any payment and personal concern regarding to this study. The authors of this manuscript declare no other relationships with any companies, whose products or services may be related to the subject matter of the article., (© 2024. The Author(s).)

The molecular pathological examination of solid tumors is essential not only for supporting histological diagnosis but also for detecting hereditary variations and predictive biomarkers. Analyzing predictive markers is fundamental to personalized cancer therapy, directly affecting patient care through pathological testing. These analyses employ both traditional immunohistochemical staining methods and molecular genetic techniques. In both approaches, preanalytics is of critical importance, necessitating the adoption of standardized and reproducible processes. Molecular diagnostics in colorectal cancer focuses on detecting activating mutations in the MAPK pathway (KRAS, NRAS, BRAF), as well as evaluating microsatellite instability and HER2 amplification. Immunohistochemical methods can effectively identify biomarkers for gastric cancers, including the novel claudin18.2. The responsiveness of gastrointestinal stromal tumors to imatinib requires validation via molecular testing. Patients diagnosed with pancreatic cancer may see enhanced survival rates by targeted therapy addressing microsatellite instability and BRCA mutations. In bile duct malignancies, especially intrahepatic cholangiocarcinoma of the small duct variant, the analysis of IDH1 mutations and FGFR2 fusions presents new treatment prospects.

High malignancy potential gastric gastrointestinal stromal tumors (HMP-gGISTs) generally require surgical resection. However, the necessity of lymph node removal (LR) for patients with such tumors remains unclear. Therefore, we conducted a population-based study to analyze the impact of LR on the long-term prognosis of patients with HMP-gGISTs. Patients with HMP-gGISTs were gathered from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was utilized to address potential selection bias. Overall survival (OS) and cancer-specific survival (CSS) were evaluated using Kaplan-Meier analyses and multivariate Cox proportional hazards models. A total of 840 patients with HMP-gGISTs were included in the study, with 317 undergoing LR and 523 not undergoing LR. The prognosis for OS (P = 0.026) and CSS (P < 0.001) in the LR group was worse compared to the No-LR group. After PSM, 634 patients were matched for comparison. The results showed that the OS (P = 0.028) and CSS (P = 0.006) in the LR group remained poorer than those in the No-LR group. Subgroup analysis further indicated that patients who did not undergo LR had a better prognosis. Our findings suggest that LR may not improve the prognosis of patients with HMP-gGISTs, implying that LR may not be necessary for these patients., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Qiao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Purpose: The immunonutritional status of cancer patients has a profound impact on lifespan. Prognostic Nutritional Index (PNI) evaluates prognosis in operated patients with both neoplastic and non-neoplastic conditions. This study estimates the overall survival (OS) of Mexican patients operated on gastrointestinal stromal tumors (GIST) based on PNI., Methods: Immune-nutritional status was retrospectively analyzed in a cohort of 104 patients operated on GIST. Receiver operating characteristic (ROC) curves and X-tile software were used to estimate the optimal cutoff point and predict OS stratifying patients by PNI. Survival curves were obtained through Kaplan-Meier and log-rank methods. Multivariate analysis of survival was performed by Cox regression., Results: PNI (≥ 36.5) (p = 0.024) and mitotic index (≥ 5) (p = 0.013) were the only independent prognostic scores; the PNI-high group had better survival with 81.5% less risk of death (HR = 0.185). High PNI was correlated with favorable characteristics, i.e., low/intermediate risk (p = 0.046), reduced mitotic index (< 5) (p = 0.001), and younger age (< 55 years, p = 0.047)., Conclusions: PNI ≥ 36.5 entails a better prognosis for Mexican patients with surgically resected GIST. PNI represents a simple, reliable, and cost-effective prognostic tool, besides the pathological approach., Competing Interests: Declarations. Ethics approval: This is an observational study. The Instituto Nacional de Cancerología Ethics on Research Committee has confirmed no ethical approval is required. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Abstract: Extragastrointestinal stromal tumor (EGIST) in the posterior mediastinum is very rare. Herein, we report FDG PET/CT findings of posterior mediastinum EGIST in a 77-year-old man. On FDG PET/CT, it manifested as a solitary posterior mediastinum mass with heterogeneous necrosis and intense FDG uptake. The final pathology supported a diagnosis of EGIST. This case hints us when we encounter a soft tissue mass with intense FDG uptake in the posterior mediastinum; EGIST should be regarded as a differential diagnosis., Competing Interests: Conflicts of interest and sources of funding: The authors have no conflicts of interest to declare. The research was supported by the 1.3.5 project for disciplines of excellence, West China Hospital, Sichuan University (ZYGD23016), China Postdoctoral Science Foundation (2024M752257), Sichuan Science and Technology Program (2022YFH0047), and NHC Key Laboratory of Nuclear Technology Medical Transformation (Mianyang Central Hospital) (grant No.2022HYX011)., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Subcutaneous gastrointestinal stromal tumors (scGISTs) are extremely rare tumors, and the analysis of their long-term prognosis remains unreported. Therefore, our objective is to analyze the long-term prognosis of patients with scGISTs using the Surveillance, Epidemiology, and End Results database., Methods: Patients diagnosed with GISTs between 2000 and 2019 were included in the study. To handle missing data, multiple imputation techniques were employed. Kaplan-Meier analysis and Cox proportional hazards models were used to evaluate overall survival (OS) and cancer-specific survival (CSS), and subgroup analyses were conducted for various variables., Results: A total of 12,882 patients were enrolled, with 12,636 diagnosed with GISTs and 246 with scGISTs. In comparison to GISTs patients, scGISTs patients exhibited inferior OS [hazard ratio (HR) 1.69, 95% confidence interval (CI) 1.45-1.98, P < 0.001] and CSS (HR 2.16, 95% CI 1.78-2.61, P < 0.001). Across various subgroups, including age, sex, surgical intervention, marital status, and chemotherapy, scGISTs patients consistently demonstrated significantly poorer OS and CSS outcomes compared to GISTs patients (P < 0.05). The 1-, 3-, and 5-year OS rates for scGISTs patients were 78.4%, 60.3%, and 49.3%, respectively, with corresponding CSS rates of 83.3%, 67.8%, and 57.4%. Notably, scGISTs patients who received surgical treatment had significantly higher 5-year OS rates (62.1% vs 30.9%, P < 0.001) and CSS rates (67.8% vs 40.0%, P < 0.001) compared to those who did not undergo surgery. Multivariate Cox regression analysis identified age, surgical status, and mitotic rate as risk factors influencing OS in scGISTs patients, while surgical status and mitotic rate were identified as risk factors affecting CSS., Conclusions: Compared to GISTs patients, scGIST patients exhibit a less favorable prognosis; nonetheless, surgical intervention has been demonstrated to enhance their prognosis., Competing Interests: Declarations. Disclosures: Luojie Liu and Xinyu Shao have no conflicts of interest or financial ties to disclose., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Imatinib therapy is the gold standard for the treatment of unresectable and metastatic gastrointestinal stromal tumors (GISTs). However, few studies have reported the long-term outcomes of the treatment., Methods: Seventy patients who underwent imatinib therapy for unresectable and metastatic GISTs were enrolled between 2001 and 2009, and follow-up data were collected until October 2023. One hundred and sixty-eight months had passed since the final enrollment. The outcome measures were patient survival and the status of GIST and imatinib therapy. The cumulative incidence of disease progression (PD) and the chronological changes in PD hazard rate (HR) were also analyzed., Results: The 5-, 10-, 15-, and 20-year overall survival rates were 64.3%, 30.0%, 16.8%, and 12.2%, respectively. Sixty of the 70 enrolled patients died before the data cutoff date: 47 (78.3%) patients died of GIST progression while the remaining 13 (21.7%) died of diseases other than GISTs. The cumulative incidence of PD logarithmically increased, and PD continued even after 10 years of treatment. PD HR decreased over time to reach the lowest value at 9.6 years after the initiation of treatment (HR 0.00027; 95% CI 0.00007-0.00174) and after that formed a small peak at 13 years (HR 0.00144; 95% CI 0.00043-0.00436)., Conclusions: Imatinib therapy showed high clinical efficacy in terms of long-term survival in GIST patients. However, patients undergoing imatinib therapy were at continuous risk of PD even after the 10-year treatment. Long-term treatment and follow-up beyond 10 years are necessary for unresectable and metastatic GIST patients., Competing Interests: Declarations. Conflict of interest: The authors declare that they have no competing interests., (© 2024. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.)

Background: The administration of adjuvant imatinib during 3 years is indicated after resection of primary localized GIST at high risk of recurrence, but many patients relapse afterwards., Methods: IMADGIST (NCT02260505) was a multicenter, open-label, randomized phase III study evaluating the maintenance of imatinib for 3 more years (6-year arm) compared with interruption (3-year arm) from the day of randomization, conducted in the French Sarcoma Group. The primary endpoint was intent-to-treat disease-free survival. Secondary endpoints included overall survival, time to imatinib resistance, response after imatinib reintroduction at relapse, and safety., Results: From 24 December 2014 to 4 April 2023, 136 patients aged ≥18 years, Eastern Cooperative Oncology Group performance status ≤2, with a localized gastrointestinal stromal tumor with an R0 or R1 surgery, and a risk of tumor recurrence ≥35% according to National Comprehensive Cancer Network (NCCN) risk classification were randomized in 14 centers. Sixty-five patients were randomized to the 3-year arm versus 71 to the 6-year arm. There were 68 males and females. Primary sites were gastric and small bowel in 60 (44%) and 64 (47%) patients, respectively. Respectively, 52 (38%) and 71 (52%) patients had a risk of relapse of 35%-70% and >70%. With a median follow-up of 55 months (interquartile range 46-59 months) after randomization, disease-free survival was significantly superior in the 6-year arm [hazard ratio: 0.40 (0.20-0.69), P = 0.0008]. Time to imatinib resistance, survival, adverse events, and quality of life were not different in the two arms., Conclusions: Three additional years of adjuvant imatinib reduces the risk of relapse in patients who have received 3 years of adjuvant imatinib with an acceptable tolerance., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: The course of subclinical gastrointestinal stromal tumors (GISTs) is variable. The management of small GISTs is not well-defined., Methods: Records of patients presenting with small GISTs with documented follow-up appointment at our institution between 2016 and 2022 were identified and reviewed. Comparative univariate analysis to compare patient and tumor characteristics and outcomes was performed., Results: Eighty-six patients were followed for a median of 3.7 years (range 0.1-20 years). The median size at presentation was 1.7 (range 0.1-2.5) cm. A total of 51.2% (n = 44) underwent surgery before or immediately after initial presentation for pain (18.2%), bleeding (15.9%), or patient preference (6.8%). Another 17.4% (n = 15) had delayed surgery for tumor growth (40%), patient preference (2.7%), bleeding (6.7%), or pain (6.7%). The remaining 31.4% (n = 27) of patients never underwent surgery for reasons that included no growth/stability (44.4%), concomitant cancer diagnosis/treatment (29.6%), comorbidities (14.8%), and patient preference (3.7%). Patients who underwent surveillance without intervention compared with those who had delayed surgery were older (71.1 vs. 60.8 years, p < 0.001) with multiple comorbidities or a concurrent cancer diagnosis (70.3% vs. 20%, p = 0.005). There were no differences in survival or rate of distant metastases. Average time to surgery in the delayed group was 2 (range 0.1-10.3) years, and 86% of these patients underwent surgery by 5.5 years after diagnosis., Conclusions: In older patients with comorbidities or concurrent cancer diagnoses, opting out of surgery does not affect survival. Conversely, younger patients, free from significant comorbidities or other diagnoses, may consider surgery or active surveillance for up to 5 years, with comparable outcomes., (© 2024. Society of Surgical Oncology.)

The purpose of this study was to determine if dual-energy CT (DECT) vital iodine tumor burden (ViTB), a direct assessment of tumor vascularity, allows reliable response assessment in patients with GIST compared to established CT criteria such as RECIST1.1 and modified Choi (mChoi). From 03/2014 to 12/2019, 138 patients (64 years [32-94 years]) with biopsy proven GIST were entered in this prospective, multi-center trial. All patients were treated with tyrosine kinase inhibitors (TKI) and underwent pre-treatment and follow-up DECT examinations for a minimum of 24 months. Response assessment was performed according to RECIST1.1, mChoi, vascular tumor burden (VTB) and DECT ViTB. A change in therapy management could be because of imaging (RECIST1.1 or mChoi) and/or clinical progression. The DECT ViTB criteria had the highest discrimination ability for progression-free survival (PFS) of all criteria in both first line and second line and thereafter treatment, and was significantly superior to RECIST1.1 and mChoi (p < .034). Both, the mChoi and DECT ViTB criteria demonstrated a significantly early median time-to-progression (both delta 2.5 months; both p < .036). Multivariable analysis revealed 6 variables associated with shorter overall survival: secondary mutation (HR = 4.62), polymetastatic disease (HR = 3.02), metastatic second line and thereafter treatment (HR = 2.33), shorter PFS determined by the DECT ViTB criteria (HR = 1.72), multiple organ metastases (HR = 1.51) and lower age (HR = 1.04). DECT ViTB is a reliable response criteria and provides additional value for assessing TKI treatment in GIST patients. A significant superior response discrimination ability for median PFS was observed, including non-responders at first follow-up and patients developing resistance while on therapy., (© 2024 The Author(s). International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Objective: Gastrointestinal stromal tumors (GISTs) are difficult to identify the risk level accurately without surgical pathological confirmation. The purpose of our study was to propose a noninvasive prediction method for predicting the malignant potential of GISTs preoperatively by using contrast-enhanced ultrasound (CEUS) with gastric distention., Methods: We reviewed 47 GISTs who underwent CEUS from April 2017 to August 2023 retrospectively, all the lesions were certificated by pathology after surgery. The age of the patient, size of the lesion, shape, necrosis, calcification in the lesion, perfusion parameters including arrival time (AT), peak intensity (PI), time to peak (TTP), and area under the curve (AUC) of the lesion and surrounding normal tissue were analyzed. Logistic regression analyses were performed. Of the 47 GISTs, 26 were high-risk and 21 low-risk tumors respectively., Results: Compared with low-risk GISTs, high-risk GIST had faster AT (7.7s vs. 11.5s, p < 0.05), higher PI (15.2dB vs. 12.5dB, p < 0.05), and larger size (4.4 cm vs. 2.2 cm, p < 0.001). In multivariate logistic regression, AT, PI, and size were significant features. The corresponding regression equation In (p/(1-p)=-5.9 + 4.5 size + 4.6 PI + 4.0 AT)., Conclusion: The size, AT, and PI of the GISTs on CEUS can be used as parameters for a noninvasive risk level prediction model of GISTs. This model may help identify the different risk levels of GISTs before surgery., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Competing Interests: The authors declare that they have no conflict of interest.

Competing Interests: The authors declare that they have no conflict of interest.

Rationale and Objectives: The objective was to assess and examine radiomics models derived from contrast-enhanced CT for their predictive capacity using the sub-regional radiomics regarding the Ki-67 proliferation index (PI) in patients with pathologically confirmed gastrointestinal stromal tumors (GIST)., Methods: In this retrospective study, a total of 412 GIST patients across three institutions (223 from center 1, 106 from center 2, and 83 from center 3) was enrolled. Radiomic features were derived from various sub-regions of the tumor region of interest employing the K-means approach. The Least Absolute Shrinkage and Selection Operator (LASSO) regression was employed to identify features correlated with Ki-67 PI level in GIST patients. A support vector machine (SVM) model was then constructed to predict the high level of Ki-67 (Ki-67 index >8%), drawing on the radiomics features from each sub-region within the training cohort., Results: After features selection process, 6, 9, 9, 7 features were obtained to construct SVM models based on sub-region 1, 2, 3 and the entire tumor, respectively. Among different models, the model developed by the sub-region 1 achieved an area under the receiver operating characteristic curve (AUC) of 0.880 (95% confidence interval [CI]: 0.830 to 0.919), 0.852 (95% CI: 0.770-0.914), 0.799 (95% CI: 0.697-0.879) in the training, external test set 1, and 2, respectively., Conclusion: The results of the present study suggested that SVM model based on the sub-regional radiomics features had the potential of predicting Ki-67 PI level in patients with GIST., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Competing Interests: The authors declare that they have no conflict of interest.

Background: Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors affecting the digestive tract, comprising approximately 0.1-3% of all gastrointestinal cancers. ROR2, a member of the receptor tyrosine kinase orphan receptor subfamily, functions as a signaling receptor for Wnt ligands. This study aims to assess the prognostic significance of ROR2 expression in GIST., Methods: A total of 56 paraffin-embedded blocks of GIST cases originating from different parts of the gastrointestinal tract (GIT) were included in this study. Immunohistochemistry was performed to detect ROR2 expression., Results: ROR2 expression was observed in 71.4% of GIST cases, and strong intensity of ROR2 staining was significantly associated with prolonged overall survival of GIST patients (p = 0.048). Furthermore, ROR2 positivity and the percentage of immunostaining showed an inverse correlation with tumor progression., Conclusions: GIST cases displaying ROR2 positivity exhibit a reduced likelihood of disease progression and demonstrate favorable prognostic characteristics., Competing Interests: Declarations. Competing Interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

To develop and validate a machine learning (ML) model which combined computed tomography (CT) semantic and radiomics features to preoperatively predict Ki-67 expression in gastrointestinal stromal tumors (GISTs) patients. We retrospectively collected the clinical, imaging and pathological data of 149 GISTs patients. We randomly assigned the patients in a ratio of 7:3 to a training set (104 cases) and a validation (45 cases) set. We divided the patients into low and high Ki-67 expression group according to postoperative pathology. CT semantic features were analyzed from preoperative enhancement CT images and radiomics features were extracted from venous phase-enhanced images. We used intraclass correlation coefficient, maximal relevance and minimal redundancy and least absolute shrinkage and selection operator method to screen radiomics features and build radiomics label. 6 ML models were used for model construction. Receiver operating characteristic curves were used to evaluate the predictive efficiency of ML models. SHAP analysis was used to explain the contribution of different variables and their risk threshold. AUC of radscores in predicting Ki-67 expression of GIST patients were 0.749 and 0.729 in training and validation set. Among the 6 ML models, SVM exhibited best prediction accuracy. AUC of SVM model in predicting Ki-67 expression of GIST patients were 0.840, 0.767 and 0.832 in training, validation and test set. SHAP analysis showed that radscores and tumor diameter had highly positive contribution to the model. Therefore, the interpretable SVM model can predict Ki-67 expression of GISTs patients individually before surgery, which can provide reliable imaging biomarkers for clinical treatment decisions., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethics statement: The studies involving human participants were reviewed and approved by Institutional review board of the Affiliated Huaian No.1 People’s Hospital of Nanjing Medical University (KY-2022-045-01). Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements., (© 2024. The Author(s).)

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the gastrointestinal tract, and tyrosine kinase inhibitors (TKIs) have achieved great success in the treatment of GISTs. The role and value of surgery in advanced GISTs are still controversial. This article aims to review the progress related to surgery for advanced GIST in the context of targeted therapy, particularly exploring the issues related to the combination of surgery and targeted therapy. Studies have shown that selected advanced GISTs can benefit from surgery, but there is still a lack of universally accepted screening criteria and operational norms, and multiple factors affect the effectiveness of surgical treatment for advanced GISTs. Different surgical strategies should be developed for imatinib-resistant GISTs or multiple TKI-resistant GISTs. During the period when the tumors respond to imatinib, cytoreductive surgery is most likely to improve the survival of patients. Early or localized progression should be identified and promptly intervened with surgery. At present, there are few studies on sunitinib or regorafenib combined with surgery, and their feasibility and value are still controversial. Ripretinib combined with cytoreductive surgery may be a new breakthrough point.

The objective of the study was to investigate whether special stains can differentiate gastrointestinal stromal tumors (GISTs) and gastrointestinal leiomyomas (GILs). In this retrospective study, 39 cases of GISTs (diameter, 0.2-8.8 cm) and 75 cases of GILs (diameter, 0.2-4.5 cm) were recruited, all biopsy specimens were obtained by endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR) excision, and the depth of excision included the whole mucosa, mucosal myometria, and most submucosa. GISTs and GILs were the most common types of mesenchymal tumors found anywhere along the gastrointestinal (GI) tract, from the esophagus to the rectum. GISTs were often associated with a higher risk of malignancy. In this study, the gender, age of onset, size and sites of the lesions, together with the number of mucosal or lamina propria lesions all have significant differences, nevertheless, there was no significant difference in cell morphology of GISTs and GILs tested by hematoxylin eosin (H&E) stain, and all showed low echo areas by EUS examination. In this retrospective study, the GISTs and GILs had been diagnosed by immunohistochemistry combined with clinical morphology. Subsequently, special stains including Masson's trichrome (MT) stain, Alcian blue periodic acid-Schiff (AB-PAS) stain (pH 2.5), Wright-Giemsa (W-G) stain and periodic acid-Schiff (PAS) combined with diastase periodic acid-Schiff (D-PAS) stains were also applied in the diagnosis, the retrospective study results showed that 92.3% GISTs were stained blue with MT stain, 97.3% GILs were stained red with MT stain (P < 0.01), almost all GISTs were PAS-negative (light purple), in contrast, all GILs were PAS-positive (rose red) (P < 0.01), all of these experiments set control using the blood vessels stained by MT and AB-PAS stains. Nevertheless, there was no significant difference between GISTs and GILs stained by W-G stain. These obvious and meaningful differential results were also confirmed in the detection of new GISTs and GILs cases using MT and AB-PAS stains. In conclusion, MT and AB-PAS stains could also identify GISTs and GILs cases, particularly, AB-PAS was more sensitive and more specific, providing a more cost-effective, simple, and high sensitivity and specificity inspection methods, which should be noticed and widely used in the future, especially in resource-limited grass-roots testing institution or in cases with inconclusive immunostains or insufficient material., Competing Interests: Declarations. Ethics approval and consent to participate: All the recruits of this present study were informed and have written informed consent to participate the research, meanwhile, this present study was approved by the ethics committee of Hubei Provincial Hospital of Integrated Chinese and Western Medicine. Consent for publication: All participants were informed and consented to the publication of the results of the study. This present manuscript has not been published or accepted for publication, and the department of pathology, Hubei Provincial Hospital of Integrated Chinese and Western Medicine was fully aware of this submission, and was consent for publication. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Purpose: To identify more reliable imaging and serological indicators for predicting Ki-67 expression and malignant potential in gastrointestinal stromal tumors, as well as to develop a preoperative prediction model with clinical utility., Patients and Methods: This study retrospectively analyzed patients with gastrointestinal stromal tumors (GIST) diagnosed at the First Affiliated Hospital of Jinzhou Medical University between May 2018 and May 2024. Univariate logistic analyses, two-way stepwise regression, P-value stepwise regression, and LASSO regression were employed to screen for Ki-67 high expression and high malignant potential risk factors associated with GIST. Models were established using various regression methods; Nomograms, calibration curves, and clinical decision curves were generated for the two best prediction models., Results: Two-way stepwise regression analysis revealed that diameter (P=0.037; OR=1.22; 95% CI: 1.01 - 1.46), growth pattern (extraluminal type: P=0.028; OR=3.54; 95% CI: 1.14 - 10.94), enhancement model (P=0.099; OR=0.39; 95% CI: 0.12 - 1.20), EVFDM (P=0.069; OR=0.43; 95% CI: 0.17 - 1.07), PLR (P=0.099; OR=3.06; 95% CI: 0.81 - 11.59), and OPNI (P=0.058; OR=2.38; 95% CI: 0.97 - 5.84) are identified as independent risk factors for Ki-67 expression. Utilizing the two-way stepwise regression model to predict Ki-67 expression, the area under the curve (AUC) for the training group was 0.865 (95% CI: 0.807-0.922), while for the validation group it was 0.784 (95% CI: 0.631-0.937). The Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) for the training group were 153.360 and 174.619, respectively. Two-way stepwise regression analysis revealed that volume (P < .001, OR = 1.06; 95% CI: 1.03 - 1.09), contour (P = 0.066; OR = 0.17; 95% CI: 0.05 - 0.62), ulcer (P = 0.094; OR = 0.16; 95% CI: 0.03 - 0.98), IBSC (P = 0.008; OR = 5.27; 95% CI: 1.57 - 17.69), and OPNI (P = 0.045; OR = 0.22; 95% CI: 0.05 - 0.96) are independent risk factors for malignant potential. Utilizing the two-way stepwise regression model to predict malignant potential, the AUC for the training group was 0.950 (95% CI: 0.920 - 0.980), while for the validation group it was 0.936 (95% CI: 0.867 - 1.000). The AIC and BIC values for the training group were 96.330 and 114.552, respectively., Conclusion: Diameter, growth pattern, enhancement pattern, EVFDM, PLR, and OPNI are independent risk factors for GIST with high Ki-67 expression. Additionally, volume, contour, ulceration, IBSC, and OPNI serve as independent risk factors for GIST with high malignant potential. The preoperative models developed using CT images can predict the malignant potential and Ki-67 expression status of GIST to a certain extent. When combined with serological indicators, these models' predictive performance can be further enhanced., Competing Interests: Declarations Ethics approval and consent to participate This study adhered to ethical standards and was approved by the Ethics Review Committee of the First Affiliated Hospital of Jinzhou Medical University (No: KYLL202445), which waived the need for consent to participate due to the retrospective design of this research. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Background: To investigate whether an additional gastrojejunostomy reduces the incidence of delayed gastric emptying (DGE) following a distal segmental duodenectomy for duodenal and proximal jejunal gastrointestinal stromal tumors (GIST)., Materials and Methods: This retrospective review of the GIST database at Peking University Cancer Hospital included 50 patients who underwent distal segmental duodenectomies for primary GIST in the duodenum or proximal jejunum within 20 cm of Treitz's ligament between January 2008 and December 2023. The patients were divided into two groups: non-bypass (without gastrojejunostomy) and bypass (with gastrojejunostomy and Braun's jejunojejunostomy). Perioperative characteristics and postoperative complications were analyzed., Results: Among the 50 patients, 27 underwent duodenojejunostomies without gastrojejunostomies and 23 with gastrojejunostomies and Braun's jejunojejunostomies. The incidence of grade B-C DGE was significantly lower in the bypass group (43.5% vs. 74.1%, p = 0.028). In addition, non-bypass surgery was an independent risk factor for increased grade B-C DGE (OR 3.67, 95% CI 1.07-12.64, p = 0.039). The bypass group showed a trend towards a shorter postoperative hospital stay (median: 14 days, range: 10-56) compared to the non-bypass group (median: 28 days, range: 6-75), but this difference did not reach statistical significance (p = 0.070). Operative time (min) was significantly longer in the multi-visceral resection group (381.0 ± 108.8 vs. 227.3 ± 87.6, p < 0.001), for tumors ≥ 6.3 cm compared to < 6.3 cm (337.0 ± 116.4 vs. 228.3 ± 99.8, p = 0.002), and in patients with positive preoperative symptoms versus asymptomatic patients (319.9 ± 118.0 vs. 210.2 ± 90.3, p = 0.031)., Conclusion: The addition of gastrojejunostomy and Braun's jejunojejunostomy in distal segmental duodenectomy can reduce the incidence of grade B-C DGE, potentially facilitating timely adjuvant imatinib therapy. Future multicenter studies are needed to confirm these findings., Competing Interests: Declarations Ethics approval and consent to participate This study received approval from the institutional ethics committee and adhered to the principles outlined in the 1964 Helsinki Declaration, along with its subsequent amendments or comparable ethical standards. Written informed consent was obtained from each participating patient, ensuring compliance with ethical guidelines. The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. We have obtained consent from all authors and they have agreed to publish the results of this study. Consent for publication The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Purpose: The prognosis of patients with metastatic GIST and imatinib-sensitive primary mutations has significantly improved. However, limited data are available to inform patients about outcomes across different lines of treatment. This retrospective analysis aims to evaluate patient outcomes at a large German GIST referral center over the past 15 years., Patients and Methods: Overall survival (OS) and progression-free survival (PFS) were analyzed in patients with metastatic GIST, with diagnosis of metastases between 2008 and 2021, when at least three lines of treatment were available in Germany (n = 174)., Results: The median overall survival far exceeds historical data for patients with primary exon 11 and exon 9 mutations (median OS in palliative treatment with imatinib: 7.1 years; median OS in second-line palliative treatment with sunitinib: 2.9 years; median OS in third-line palliative treatment with regorafenib: 1.9 years). Among those patients who received palliative imatinib treatment, no significant difference in median OS survival was observed between those who had received perioperative imatinib for localized disease and those who did not. Furthermore, the location of metastases significantly impacted survival, whereas the time between the initial diagnosis and the diagnosis of metastases had no significant effect on survival., Conclusion: In conclusion, this study provides a novel, real-world reference for survival outcomes in patients with metastatic GIST., (© 2024. The Author(s).)

Rationale: Schwannomas are common peripheral nerve tumors originating from Schwann cells, primarily occurring in the head and neck, limbs, and trunk. Schwannomas occurring in the mesocolon are rare and often have no specific manifestations. Abdominal schwannomas need to be differentiated from common abdominal tumors such as gastrointestinal stromal tumors., Patient Concerns: We report a case of a mesocolic schwannoma in a 59-year-old female presenting with gastrointestinal symptoms of acid reflux. At an outside hospital, gastroscopy, colonoscopy, and abdominal computed tomography scans revealed a soft tissue mass adjacent to the greater curvature of the stomach, leading to a suspicion of a gastric mesenchymal tumor., Diagnoses: Mesocolic schwannoma., Interventions: Laparoscopy was performed at our hospital. Intraoperatively, the tumor was found to be closely related to the transverse colon and was initially diagnosed as a mass originating from the transverse colon. Consequently, a resection of the mass along with the adherent portion of the transverse colon was performed. Postoperative pathology and immunohistochemistry confirmed that the tumor was a schwannoma of the mesentery and did not originate from the transverse colon., Outcomes and Lessons: Schwannomas can be distinguished from gastrointestinal stromal tumors by immunohistochemical staining, and surgical treatment is effective for benign schwannomas., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Gastrointestinal stromal tumor (GISTs) are clinically heterogenous exhibiting varying degrees of disease aggressiveness in individual patients. We comprehensively describe the genomic and transcriptomic landscape of a cohort of 117 GISTs including 31 low-risk, 18 intermediate-risk, 29 high-risk, 34 metastatic and 5 neoadjuvant GISTs from 105 patients. GISTs have notably low tumor mutation burden but widespread copy number variations. Aggressive GISTs harbor remarkably more genomic aberrations than low-/intermediate-risk GISTs. Complex genomic alterations, chromothripsis and kataegis, occur selectively in aggressive GISTs. Despite the paucity of mutations, recurrent inactivating YLPM1 mutations are identified (10.3%, 7 of 68 patients), enriched in high-risk/metastatic GIST and functional study further demonstrates YLPM1 inactivation promotes GIST proliferation, growth and oxidative phosphorylation. Spatially and temporally separated GISTs from individual patients demonstrate complex tumor heterogeneity in metastatic GISTs. Finally, four prominent subtypes are proposed with different genomic features, expression profiles, immune characteristics, clinical characteristics and subtype-specific treatment strategies. This large-scale analysis depicts the landscape and provides further insights into GIST pathogenesis and precise treatment., (© 2024. The Author(s).)

Objective: The aim of this study was to develop and assess a radiomics model utilizing multiparametric magnetic resonance imaging (MRI) for the prediction of preoperative risk assessment in gastrointestinal stromal tumors (GISTs)., Material and Methods: An analysis was performed retrospectively on a group of 121 patients who received a histological diagnosis of GIST. They were then divided into two sets, with 85 in the training set and 36 in the validation set through random partitioning. Radiomics features from five MRI sequences, totaling 600 per patient, were extracted and subjected to feature selection utilizing a random forest algorithm. The discriminatory efficacy of the models was evaluated through receiver operating characteristic (ROC) and precision-recall (P-R) curve analyses. Model calibration was assessed via calibration curves. Subgroup analysis was performed on GISTs with a pathological maximum diameter equal to or less than 5 cm. Furtherly, Kaplan-Meier (K-M) curves and log-rank tests were used to compare the differences in survival status among different groups. Cox regression analysis was employed to identify independent prognostic factors and to construct a prognostic prediction model., Results: The clinical model (Model C ) displayed limited predictive efficacy in the context of GIST. Conversely, a radiomics model (Model R ) incorporating five parameters exhibited robust discriminative capabilities across both the training and validation sets, yielding area under the ROC curve (AUC) values of 0.893 (95% confidence interval [CI]: 0.807-0.949) and 0.855 (95% CI: 0.732-0.978), respectively. The F1 max scores derived from the P‑R curves were 0.741 and 0.842 for the training and validation sets, respectively. Noteworthy was the exclusion of the two-dimensional tumor diameter and tumor location when constructing a hybrid model (Model CR ) that amalgamated radiomics and clinical features. Model R demonstrated a substantially enhanced discriminative capacity in the training set compared with Model C (p < 0.005). The net reclassification improvement (NRI) corroborated the superior performance of Model R over Model C , thereby enhancing diagnostic accuracy and clinical applicability. Patients in the high-risk group had significantly worse recurrence-free survival (RFS, p < 0.001) and overall survival (OS, p = 0.004), and the radiomics signature is an independent risk factor for RFS. The extended model incorporating the radiomics signature outperformed the baseline model in terms of risk assessment accuracy (p < 0.001)., Conclusion: Our investigation underscores the value of integrating radiomics analysis in conjunction with machine learning algorithms for prognostic risk stratification in GIST, presenting promising implications for informing clinical decision-making processes as well as optimizing management strategies., Competing Interests: Declarations. Conflict of interest: J. Du, L. Yang, T. Zheng and D. Liu declare that they have no competing interests. This retrospective study involved human participants. This study was approved by the Institutional Ethics Committee of the First Hospital of Qinhuangdao and conducted in accordance with the ethical standards of the 1964 Declaration of Helsinki and its later amendments. As this is a retrospective study using anonymized data, the Ethics Committee approved a waiver of informed consent from participants. The supplement containing this article is not sponsored by industry., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

The diagnosis of gastrointestinal stromal tumors (GISTs) is generally straightforward using a combination of histologic evaluation and pertinent immunohistochemical staining with CD117/kit and DOG-1 (discovered on GIST) antibodies. However, this tumor can be challenging in cases with an unusual morphology, in limited biopsies, for those in uncommon sites, post-treatment, and when other neoplasms express CD117/kit and DOG-1, thereby mimicking GIST. Finding epithelioid GISTs in the stomach in younger patients should prompt testing for succinate dehydrogenase (SHD)-deficiency using immunohistochemical staining for subunit B (SDHB). However, SDH-deficient GISTs can also arise in older patients, or as part of the Carney triad or Carney-Stratakis syndrome. GISTs with PDGFRA mutations can also prove difficult if they lack kit expression. It is also important to consider morphologic and immunophenotypic changes associated with treatment, including the potential absence of kit expression, particularly in GISTs that have metastasized. Therefore, obtaining clinical information regarding prior therapy with a tyrosine kinase inhibitor (TKI) is crucial., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Gastric gastrointestinal stromal tumors (GISTs) are mesenchymal neoplasms with variable behavior characterized by differentiation toward the interstitial cells of Cajal occurring anywhere in the gastrointestinal stromal tract. The management of GIST was revolutionized by the introduction of imatinib, a KIT inhibitor, which has become the standard first-line treatment for metastatic GIST. However, despite a clinical benefit rate of 80%, the majority of patients with GIST experience disease progression after 2 to 3 years of imatinib therapy. This shows the need for novel treatment approaches for imatinib refractory GISTs. The checkpoint proteins B7-H3 and B7-H4 inhibit the activation and function of T cells by potently suppressing the proliferation, cytokine production, and cytotoxicity of activated T cells, which is a mechanism for immune escape. This study aims to clarify B7-H3 and B7-H4 expression in gastric GISTs using immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR). We confirmed B7-H3 expression (H-score ≥50 points) in 92% and B7-H4 expression in 0% of GIST samples. We examined B7-H3 mRNA expression in 3 representative GIST samples, each having their respective immunostained areas detected by RT-PCR. B7-H3 is expressed at a particularly high rate in GISTs. This suggests that B7-H3 might operate as part of an immune checkpoint in GISTs., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The primary purpose of the study was to explore the clinical efficacy of the novel snare assisted endoscopic resection of extraluminal growing gastric gastrointestinal stromal tumors (gastric GISTs) using external traction, and the secondary purpose was to compare the novel snare assisted endoscopic resection of extraluminal GISTs with the standard laparoscopic procedure., Methods: We retrospectively analyzed the patients who underwent novel external traction assisted endoscopic resection or laparoscopic resection for their extraluminal gastric GIST ≤5 cm in diameter., Results: A total of 111 patients (27 in the endoscopic group and 84 in the laparoscopic group) were included in this study. There was no significant difference in tumor diameter and complication rate between the two groups. The overall procedure time was slightly higher in the endoscopic group compared to the laparoscopic group (P = 0.034). However, postoperative hospitalization time (P < 0.001) and postoperative fasting time (P = 0.005) were shorter in the endoscopic group compared to the laparoscopic group., Conclusion: Snare external traction-assisted endoscopic resection of extraluminal growing gastric GISTs is safe and effective, and it provides a new adjunctive method for endoscopic resection of GIST., Competing Interests: Conflict of interest 1) The scientific guarantors of this publication are Xin-guang Cao. 2) The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article. 3) The authors of this manuscript declare that they have no conflict of interests. 4) The protocol was approved by The First Affiliated Hospital of Zhengzhou University (No.2022-KY-1236-001) and informed consent was waived., (Copyright © 2024 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

Background: Studies have demonstrated comparable outcomes between laparoscopic and open resection of gastrointestinal stromal tumor (GIST). We sought to compare outcomes among robotic, laparoscopic, and open resection of gastric GIST in the era of expanding minimally invasive surgery., Methods: A retrospective analysis was performed of adult patients with gastric GIST undergoing definitive surgery using the National Cancer Database from 2010 to 2020, excluding cases converted to open. Patients were stratified into minimally invasive surgery (MIS), (combined robotic (R) and laparoscopic (L)), and open (O). Hospital length of stay (LOS), 30-day mortality, 90-day mortality, and margin status were assessed. Subgroup analysis was performed to evaluate outcomes between R and L cohorts. Entropy balancing was used to adjust for intergroup differences. Kaplan-Meier survival estimates were used to compare unadjusted 5-year survival., Results: Of the 15,022 patients (R = 10.4%, L = 44.3%, O = 45.3%), 63.2% were stage I and 70.6% underwent partial gastrectomy. MIS approach was associated with shorter hospital LOS (β: - 2.58; 95% CI: - 2.82 to - 2.33) and lower odds of 30-day (OR 0.45; 95% CI: 0.30-0.68) and 90-day mortality (OR 0.54; 95% CI: 0.39-0.74) compared to O. Likelihood of R0 resection similar between groups (OR 1.00; 95% CI: 0.88-1.14). Hospital LOS (β: + 0.25; 95% CI: - 0.14-0.64), odds of 30-day (OR 0.99; 95% CI: 0.40-2.46) and 90-day mortality (OR 0.89; 95% CI: 0.47-1.70), and rate of R0 resection (OR 1.02; 95% CI: 0.82-1.27) were comparable between R and L cohorts. Compared to O, MIS approach was associated with improved 5-year OS (log rank p < 0.001). Overall survival was not significantly different between R and L (log rank p = 0.44)., Conclusion: These findings suggest that MIS approach may be considered for resection of gastric GIST in select patients. Among patients receiving an MIS approach, the robotic technique can be considered an oncologically safe alternative to laparoscopic surgery., (© 2024. The Author(s).)

Background: Synchronous rectal and prostate malignancies are rare and standard treatment guidelines have not yet been established. 1-3 Combined robotic rectal and prostate surgery represents a potentially excellent approach for managing synchronous rectal and prostate malignancies, offering the advantages of a minimally invasive procedure. 4 METHODS: A 78-year-old male with a history of hypertension and type 2 diabetes presented with 3 months of dyschezia and dysuria. Diagnostic colonoscopy revealed a submucosal mass 3 cm from the anal verge in the anterior wall of the rectum, with abnormal carcinoembryonic antigen and prostate-specific antigen levels. Pelvic computed tomography (CT) indicated indistinct boundaries between the rectal mass and the prostate, suggesting potential invasion. CT-guided biopsies confirmed a rectal gastrointestinal stromal tumor (GIST) and prostatic acinar adenocarcinoma. After 3 months of neoadjuvant therapy with imatinib mesylate and bicalutamide, significant tumor reduction was achieved. 5 Subsequently, the patient underwent simultaneous robotic sphincter-preserving rectal resection and prostatectomy, starting with the prostatectomy, followed by rectal tumor excision and ending with bowel reconstruction and vesicourethral anastomosis using a running suture technique., Results: The operation time was 220 min and the estimated blood loss was 50 mL. No surgical complications were encountered and all resected margins were free of tumor, indicating a complete excision. The patient recovered well and was discharged on the seventh postoperative day. Follow-up at 3 months showed no evidence of recurrence or functional impairments., Conclusion: Simultaneous robotic sphincter-preserving local rectal resection and prostatectomy can be feasibly and safely performed following neoadjuvant therapy in cases of synchronous rectal GIST and prostate cancer., (© 2024. Society of Surgical Oncology.)

Patients with gastro-intestinal stromal tumors (GISTs) undergoing tyrosine kinase inhibitor therapy are monitored with regular computed tomography (CT) scans, exposing patients to cumulative radiation. This exploratory study aimed to evaluate circulating tumor DNA (ctDNA) testing to monitor treatment response and compare changes in ctDNA levels with RECIST 1.1 and total tumor volume measurements. Between 2014 and 2021, six patients with KIT proto-oncogene, receptor tyrosine kinase (KIT) exon-11-mutated GIST from whom long-term plasma samples were collected prospectively were included in the study. ctDNA levels of relevant plasma samples were determined using the KIT exon 11 digital droplet PCR drop-off assay. Tumor volume measurements were performed using a semi-automated approach. In total, 94 of 130 clinically relevant ctDNA samples were analyzed. Upon successful treatment response, ctDNA became undetectable in all patients. At progressive disease, ctDNA was detectable in five out of six patients. Higher levels of ctDNA correlated with larger tumor volumes. Undetectable ctDNA at the time of progressive disease on imaging was consistent with lower tumor volumes compared to those with detectable ctDNA. In summary, ctDNA levels seem to correlate with total tumor volume at the time of progressive disease. Our exploratory study shows promise for including ctDNA testing in treatment follow-up., (© 2024 The Authors. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Gastrointestinal stromal tumors (GISTs) are sarcomas that arise from the muscular layer of the gastrointestinal tract. The stomach is the most common location, followed by the small intestine. Surgical resection is the cornerstone of treatment; extensive margins and lymphadenectomy are not routinely required. Commonly utilized resection techniques include wedge gastrectomy, excision and closure of the gastrotomy, and anterior gastrotomy access with internal wedge resection. Tyrosine kinase inhibitors can be utilized in the neoadjuvant setting for cases where a reduction in tumor size would optimize resection, and in the adjuvant setting for high-risk tumors. In select cases, metastasectomy may improve prognosis., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Sarcomas are rare mesenchymal tumors with a propensity for hematogenous metastasis. Gastrointestinal stromal tumor (GIST) is the most common histologic subtype and the most common source of hepatic metastases. In the case of metastatic GIST, neoadjuvant imatinib can be used as a selection tool for the judicious application of surgery, where treatment-responsive patients who undergo resection to prevent the development of treatment-resistant clones have associated 10-year actuarial survival of 40%. Further advances for many of the non-GIST sarcoma subtypes will depend on the development of improved systemic therapies and evaluation of their activity in subtype or molecularly defined trials., Competing Interests: Disclosure Drs B.L. Ecker, M.J. Cavnar, and R.P. DeMatteo do not have any relevant conflicts of interest to disclose. Dr R.G. Maki reports research support to the institution from SARC: Sarcoma Alliance for Research through Collaboration., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Gastrointestinal stromal tumors (GISTs) present a complex clinical landscape, where precise preoperative risk assessment plays a pivotal role in guiding therapeutic decisions. Conventional methods for evaluating mitotic count, such as biopsy-based assessments, encounter challenges stemming from tumor heterogeneity and sampling biases, thereby underscoring the urgent need for innovative approaches to enhance prognostic accuracy., Objective: The primary objective of this study was to develop a robust and reliable computational tool, PROMETheus (Preoperative Mitosis Estimator Tool), aimed at refining patient stratification through the precise estimation of mitotic count in GISTs., Methods: Using advanced Bayesian network methodologies, we constructed a directed acyclic graph (DAG) integrating pertinent clinicopathological variables essential for accurate mitotic count prediction on the surgical specimen. Key parameters identified and incorporated into the model encompassed tumor size, location, mitotic count from biopsy specimens, surface area evaluated during biopsy, and tumor response to therapy, when applicable. Rigorous testing procedures, including prior predictive simulations, validation utilizing synthetic data sets were employed. Finally, the model was trained on a comprehensive cohort of real-world GIST cases (n=80), drawn from the repository of the Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Humanitas Research Hospital, with a total of 160 cases analyzed., Results: Our computational model exhibited excellent diagnostic performance on synthetic data. Different model architecture were selected based on lower deviance and robust out-of-sample predictive capabilities. Posterior predictive checks (retrodiction) further corroborated the model's accuracy. Subsequently, PROMETheus was developed. This is an intuitive tool that dynamically computes predicted mitotic count and risk assessment on surgical specimens based on tumor-specific attributes, including size, location, surface area, and biopsy-derived mitotic count, using posterior probabilities derived from the model., Conclusions: The deployment of PROMETheus represents a potential advancement in preoperative risk stratification for GISTs, offering clinicians a precise and reliable means to anticipate mitotic counts on surgical specimens and a solid base to stratify patients for clinical studies. By facilitating tailored therapeutic strategies, this innovative tool is poised to revolutionize clinical decision-making paradigms, ultimately translating into improved patient outcomes and enhanced prognostic precision in the management of GISTs., (©Salvatore Lorenzo Renne, Manuela Cammelli, Ilaria Santori, Marta Tassan-Mangina, Laura Samà, Laura Ruspi, Federico Sicoli, Piergiuseppe Colombo, Luigi Maria Terracciano, Vittorio Quagliuolo, Ferdinando Carlo Maria Cananzi. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 22.10.2024.)

Purpose: The infiltration of immune cells and their roles of the infiltrating-immune cells in gastrointestinal stromal tumor (GIST) is still unclear. We aimed to discover the infiltration cell types and the relationship between the infiltrating-immune cells and the progression of GIST., Experimental Design: Single-cell RNA sequencing were performed to discover types of the infiltrating-immune cells and to analyze CellChat between cells. Immunohistochemistry of 80 GIST samples were used to clarify the relation between macrophages and recurrence risk. In vitro , flow cytometry and Real-time PCR were performed to uncover a potential mechanism of tumor cell regulation of macrophages., Results: Tumor cells, macrophages, and T-cells were the predominant cell types. The MIF/CXCR4 axis was the most common ligand-receptor interaction between macrophages and tumor cells. As the risk increased, expression levels of CD68, CD206, MIF, and CXCR4 gradually increased. In vitro , we found that GIST882 was able to secrete MIF and GIST882 cell supernatant upregulated M2 polarization. Real-time PCR showed that expression levels of IL-10 mRNA and Arginase-1 mRNA were also the highest in the GIST882 cell supernatant group., Conclusions: These findings identify that macrophages are the most abundant infiltrating cells in GIST. The MIF/CXCR4 axis is the most common ligand-receptor interaction between macrophages and tumor cells. GIST cells can regulate macrophage M2 polarization through the MIF/CXCR4 axis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Xiao, Xu, Yang, Zhao, Xie, Lei and Wu.)

Objective: To investigate the safety and efficacy of endoscopic subserosal dissection for patients with submucosal tumors in the upper gastrointestinal tract., Methods: This retrospective single-center study included 16 patients who underwent ESSD. All patients were enrolled from July 2018 to Dec 2021. Parameters such as demographics, size, resection margin, complications, pathological features, procedure time and follow-up were investigated and analyzed., Results: Our study achieved 100% en bloc resection and 100% R0 resection. The most common location was the corpus with a mean tumor size of 2.78 ± 1.56 cm. The mean age, procedure time, were 53.4 ± 10.3 years, 85.31 ± 46.64 min respectively. Acocording to National Institutes of Health classification, 7 (13, 53.85%), 5 (13, 38.46%) ,and 1 (13, 7.69%) objects belonged to the very low, low, and intermediate classification, respectively. Immunohistochemistry results showed a 100% positive rate of CD34, DOG-1, CD117, and Ki67. A mean follow-up of 9.3 ± 2.5 months showed no recurrence or metastasis., Conclusions: ESSD is effective and safe surgical procedure for curative removal of gastrointestinal submucosal tumors in the upper gastrointestinal tract, and it can be preferred for patients with no metastasis., (© 2024. The Author(s).)

Background: Effective management of adverse events is required to maintain sufficient imatinib dosing when treating patients with gastrointestinal stromal tumors (GISTs). Skin rash is a common adverse event of imatinib, which can be effectively controlled by systemic steroid treatment without imatinib dose modification or interruption. However, the impact of the use of systemic steroids on the efficacy of imatinib treatment remains unclear., Methods: Between October 2014 and February 2022, 277 consecutive patients from a prospective registry of GIST patients were included as the study population. Patients who started systemic steroids due to grade ≥ 3 skin rash or grade 2 skin rash with grade 2 pruritis were classified as the steroid group, whereas patients who did not develop a skin rash or those who did not require steroids for a mild skin rash were classified as the control group. Efficacy outcomes were compared between the two groups., Results: Among the 277 patients, 30 (10.8%) were treated with systemic steroids for skin rash. There was no significant difference in progression free survival (PFS) or overall survival (OS) between the steroid and control groups (3-year PFS, 67.7% vs. 65.1%, p = 0.53; 3-year OS, 91% vs. 89.9%, p = 0.67, respectively). The use of systemic steroids was not an independent factor associated with PFS (hazard ratio 0.73, 95% confidence interval 0.36-1.49, p = 0.39) and OS (hazard ratio 0.37, 95% confidence interval 0.12-1.18, p = 0.09). In the steroid group, patients who successfully maintained the imatinib dosage showed a trend toward more favorable survival outcomes than those who did not (3-year PFS, 73.3% vs. 44.4%, p = 0.34; 3-year OS, 95.8% vs. 75.0%, p = 0.15, respectively)., Conclusions: The use of systemic steroids for the control of imatinib induced severe skin rash did not adversely affect the efficacy outcomes of imatinib in patients with advanced GIST., (© 2024. The Author(s).)

A patient with gastrointestinal stroma tumor (GIST) and KIT p.V559D and BRAF p.G469A alterations was referred to our institutional molecular tumor board (MTB) to discuss therapeutic implications. The patient had been diagnosed with B-cell chronic lymphocytic leukemia (CLL) years prior to the MTB presentation. GIST had been diagnosed 1 month earlier. After structured clinical annotation of the molecular alterations and interdisciplinary discussion, we considered BRAF/KIT co-mutation unlikely in a treatment-naïve GIST. Discordant variant allele frequencies furthermore suggested a second malignancy. NGS of a CLL sample revealed the identical class 2 BRAF alteration, thus supporting admixture of CLL cells in the paragastric mass, leading to the detection of 2 alterations. Following the MTB recommendation, the patient received imatinib and had a radiographic response. Structured annotation and interdisciplinary discussion in specialized tumor boards facilitate the clinical management of complex molecular findings. Coexisting malignancies and clonal hematopoiesis warrant consideration in case of complex and uncommon molecular findings., (© The Author(s) 2024. Published by Oxford University Press.)

Gastrointestinal stromal tumors (GISTs) originate from the gastrointestinal tract. GISTs originate outside the gastrointestinal tract, referred to as extra GISTs, which is rare. Primary liver gastrointestinal stromal tumor (PLGIST) and liver metastasis of gastrointestinal stromal tumor (LMGIST) may present isolated liver lesion, making it difficult to determine their origin. A 38-year-old man who presented with isolated multiple giant cystic-solid liver lesions, ultimately diagnosed as liver GIST through CT-guided fine-needle aspiration. However, distinguishing between PLGIST and LMGIST in this case is challenging due to the absence of detailed medical records of emergency small intestine resection 5 years ago. Over 2-year follow-up period, the maximum lesion size increased from 16 to 21 cm, still, no extra liver lesions were observed. This study aims to provide a review to enhance understanding of this rare liver entity, aiding in tumor diagnosis and staging., (© 2024 Wiley Periodicals LLC.)