Search

Sarcomatoid carcinoma is a rare type of tumour consisting of neoplastic cells expressing both epithelial and mesenchymal cell markers. The small intestine is a rare site for sarcomatoid carcinoma and to date, a few cases have been reported. In this manuscript, a case of jejunal sarcomatoid carcinoma in a man in his 50s is reported. A review of the literature on sarcomatoid carcinomas of small bowel is presented., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2025. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.)

A 65-year-old man presented with asymptomatic retroperitoneal mass that had been detected on ultrasonography performed during a physical screening. He had no hematochezia, hematuria or any other symptoms. Tumor markers were normal, including alpha fetoprotein, carcinoembryonic antigen, neuron-specific enolase and cancer antigen 199. Abdominal CT demonstrated a retroperitoneal mass (white arrow) accompanied by significant thickening of the jejunal wall, involving the left kidney. After enhancement, the mass showed rapid enhancement at arterial phase and venous phase, showed washout at delayed phase. Multi-planar reformation revealed the mass involving the pancreatic tail and the left renal pelvis. Surgical resection was performed and pathological examination confirmed clear cell renal cell carcinoma involving pancreas and jejunum, with immunohistochemical results as follows: CK (partly +), Vimentin (partly +), Pax-8 (+), CD10 (+), P505s (partly +), CA-IX (+), TFE-3 (-), Syn (-), CgA (-), CD56 (+), S-100 (-), SOX-10 (-), HMB-45 (-), Desmin (-),CD117 (-), DOG-1 (-), Melan-A (-), SMA (-), CD34 (+), CD31 (+), CD68 (+), Ki67 (5%+). Discussion.

We present the case of a 62-year-old man with a history of celiac disease and IgA deficiency, following a strict gluten-free diet that was admitted to our hospital for recurrent abdominal pain, fatigue and melena. Esophagogastroduodenoscopy and colonoscopy with biopsies were normal. A video-capsule endoscopy was performed and revealed a sub-stenosing, vegetating, and bleeding lesion in the first jejunal loop. He underwent laparotomic surgery with resection of the involved segment with loco-regional lymphadenectomy. The pathological report described a poorly differentiated adenocarcinoma of the jejunum, stage IIIA (pT3pN1). Analysis of next-generation sequencing (NGS) of DNA on the surgical sample revealed a likely pathogenetic variant in exon 15 of the DDR2 gene (c.2003G > A) and a TP53 non-frame-shift deletion (c.585_602del). Considering the risk of recurrence, he was candidate to 6 months of adjuvant chemotherapy with platinum salt and fluoropyrimidine. Thirty-eight months after the diagnosis, the patient is still disease free and in good clinical condition. This is the first described case of SBA with DDR2 mutation. Considering the limited therapeutic options beyond surgery for SBA, molecular analyses could become promising for the search for potential targetable alterations for treatments with new available drugs., (© 2024. Japanese Society of Gastroenterology.)

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).)

Rationale: Extraosseous Ewing sarcoma (EES) is a rare manifestation within the Ewing sarcoma tumor family (ESFT). Its clinical manifestations lack specificity, intestinal obstruction is the main symptom but can also present with abdominal pain, gastrointestinal bleeding, and other discomforts, making it prone to misdiagnosis as intestinal mesenchymal tumor., Patient Concerns: A 29-year-old male was admitted to the hospital with intestinal obstruction symptoms and abdominal CT suggesting "left abdominal occupation.", Diagnosis: The patient was initially misdiagnosed as intestinal mesenchymal tumor, and was later definitively diagnosed as abdominal Ewing sarcoma by postoperative pathology and genetic testing., Interventions: Due to the patient's surgical indication, surgical resection with exploratory laparotomy was performed and then the patient underwent systemic chemotherapy., Outcomes: Intraoperatively, we found a 15-cm tumor originating from the proximal jejunum, with invasion into the peritoneum, duodenum, jejunum, and colon. Finally, the pathological report revealed Ewing sarcoma., Lessons: Giant abdominal Ewing sarcoma with a diameter of 15 cm is rare. Considering postoperative pathology and genetic testing, abdominal Ewing sarcoma was suspected. The patient was successfully treated using surgery., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Abstract: Calcifying fibrous tumor (CFT) is a very rare benign fibroblastic tumor featuring a wide anatomical distribution and mimicking various spindle cell tumors. CFT has been documented in soft tissues, gastrointestinal tract (GIT), neck, adrenal glands, and pleura. Within the GIT, it is reported in the stomach, small bowel, large intestine, stomach, esophagus, and appendix. The occurrence of CFTs in the gastrointestinal tract presents a diagnostic dilemma, firstly due to the rarity of the lesion and secondly, due to the occurrence of a variety of other stromal lesions in the gastrointestinal tract with histological features that overlap with CFT. In the jejunum, it is extremely rare. We present one such rare case of jejunal CFT at an unusual age, complicated by jejuno-jejunal intussusception resulting in acute intestinal obstruction., (Copyright © 2024 Indian Journal of Pathology and Microbiology.)

Because small-bowel tumors are rare, prospective data on the utility of video capsule endoscopy (VCE) for their detection are limited. Current guidelines do not advocate for surveillance VCEs in patients following small-bowel tumor resection, which is mostly due to a lack of data. Here, we report an 81-year-old male patient who had undergone curative segmental ileal adenocarcinoma resection 15 years ago and another segmental jejunal adenocarcinoma resection (TNM-Classification: pT2 pN0 (0/2) G2M0) 7 years ago. He now presents with melena, progressive dyspnea, and decreased hemoglobin levels. VCE revealed local intestinal recurrence of the previously resected jejunal adenocarcinoma, leading to a second segmental jejunal resection (TNM-Classification: pT3 L1 pN0 (0/5) G2 M0). We believe that regular surveillance VCEs after the first jejunal adenocarcinoma resection might have facilitated earlier detection of tumor recurrence in this patient's case. Therefore, we suggest considering regular surveillance VCEs, at least in patients with recurrent small-bowel malignancies. However, future prospective studies are warranted to validate our findings., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

To date, there have been no reports on tertiary lymphoid structures (TLS) in primary adenocarcinoma of jejunum and ileum. In this study, we employed digital pathology image analysis software to classify and quantify TLS, and evaluated the maturity of TLS using immunohistochemistry. Molecular genetics and immunotherapy biomarker detection were performed using next-generation sequencing technology, such as tumor mutational burden (TMB) and microsatellite instability (MSI). The aim of this study was to investigate the presence, location, maturity, association with immunotherapy biomarkers, and prognostic value of TLS in primary adenocarcinoma of jejunum and ileum. Compared to secondary follicle-like TLS (SFL-TLS), intra-tumoral TLS (IT-TLS) were more likely to manifest as early TLS (E-TLS) (P = 0.007). Compared to IT-TLS, SFL-TLS had a higher propensity to occur at the invasive margin (IM) (P = 0.032) and showed a trend towards being more prevalent at the tumor periphery (P = 0.057). In terms of immunotherapy biomarkers, there was a higher trend of IM-TLS density in PD-L1(22C3) score CPS < 1 group compared to PD-L1(22C3) score CPS ≥ 1 group (P = 0.071). TMB-H was significantly associated with MSI-H (P = 0.040). Univariate survival analysis demonstrated a correlation between high SFL-TLS group and prolonged disease free survival (DFS) (P = 0.047). There was also a trend towards prolonged DFS in the E-TLS-high group compared to the E-TLS-low group (P = 0.069). The peri-tumoral TLS (PT-TLS)-high group showed a trend of prolonged overall survival (OS) compared to the PT-TLS-low group (P = 0.090). In conclusion, the majority of TLS were located at the invasive margin and tumor periphery, predominantly consisting of mature TLS, while IT-TLS were mainly immature. Notably, TMB was closely associated with MSI and PD-L1, indicating potential predictive value for immunotherapy in primary adenocarcinoma of jejunum and ileum., (© 2024. The Author(s).)

An 86 years old man was diagnosed with jejunum tumor by detail examination of anemia. Eight days after endoscopy he developed abdominal pain, an emergency surgery was performed by a diagnosis of gastrointestinal perforation. They detected perforation in jejunum and performed jejunum resection, small intestinal lymphoma was diagnosed by histopathological examination. We were talked about chemotherapy against lymphoma, he was transferred at our hospital. The first chemotherapy was provided, abdominal pain appeared at 2 days after chemotherapy. Computed tomography revealed air bubbles out of intestinal tract, we performed emergency operation. A perforation of jejunum in the part where is different from the last time was existed, we performed jejunum resection. Chemotherapy was performed postoperatively, resulted in successful progress. Lymphoma of gastrointestinal tract often causes intestinal perforations, but reports that perforations heterochrony in separate parts multiple tumors of intestine is rare. We report a case of intestinal lymphoma with 2 perforations in a short period time.

BACKGROUND Schwannomas are tumors that arise from Schwann cells that surround and support nerve cells. Most common sites for presentations are head, neck, and extremities. Schwannomas of gastrointestinal tract are rare, slow-growing tumors, usually benign, arising from gastrointestinal tract's neural plexus. They are histologically distinguishable from conventional schwannomas that arise in soft tissue or the central nervous system. Preoperative diagnosis of gastrointestinal schwannoma is challenging, requiring immunohistological confirmation of the nature of the tumor. Here, we report a case of 57-year-old woman with an incidental finding of an asymptomatic submucosal jejunal schwannoma. CASE REPORT A 57-year-old woman with a medical history of hematological disorder underwent a contrast abdominal computed tomography as part of medical follow-up. The imaging revealed the presence of a jejunal mass. The patient underwent laparoscopic surgical resection of the lesion, followed by side-to-side jejuno-jejunal anastomosis with 4-cm clear surgical margins. The final pathologic study revealed the presence of jejunal schwannoma, as tested positive for S-100 protein. The patient was discharged home on the fourth postoperative day, having an uneventful recovery. CONCLUSIONS Jejunal schwannoma are usually benign and asymptomatic, and they are often discovered incidentally during diagnostic tests for other conditions; therefore, it should be included in the differential diagnosis of gastrointestinal tumors. Surgical treatment appears to be necessary to achieve a definitive diagnosis through a biopsy of the tumor tissue. Benign jejunal schwannomas have a good prognosis.

Small bowel adenocarcinoma (SBA) is a rare tumor with an unfavorable prognosis, and due to its rarity, few studies on its treatment are available. Chemotherapy remains the standard of treatment in advanced disease. Recently immunotherapy has demonstrated to be a valid therapeutic option for many solid tumors. We reviewed the data published in literature to understand the impact of immunotherapy in this cancer.

Calcifying fibrous tumor (CFT) is a rare, benign, mesenchymal tumor. It has a slight female predominance, and it can appear in any range of age. It can be in the extremities, neck, and gastrointestinal tract, but it has also been described in other locations. Even though it is a benign lesion, recurrence has been described in some cases in the literature. A free-margin surgical resection is the recommended treatment. We present a 56 -year-old woman who underwent surgery for an intestinal obstruction associated with middle jejunum perforation. Histopathological study described the presence of a calcifying fibrous tumor. Spindle cells were positive for CD34, Factor XIIIa and vimentin. To our knowledge, this is the first case of intestinal perforation secondary to a calcifying fibrous tumor described in the literature.

Abstract: Follicular dendritic cell sarcoma of the gastrointestinal tract is a rare malignancy. We describe contrast-enhanced CT and FDG PET/CT findings in a case of jejunal follicular dendritic cell sarcoma with hepatic metastasis. The primary jejunal tumor showed inhomogeneous enhancement on contrast-enhanced CT and intense FDG uptake on PET/CT mimicking adenocarcinoma or gastrointestinal stromal tumor. The hepatic metastatic tumor showed hypovascularity on contrast-enhanced CT and mild FDG uptake on PET/CT. This case indicates that follicular dendritic cell sarcoma should be included in the differential diagnosis of the hypermetabolic intestinal lesions., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Small bowel adenocarcinoma (SBA) remains a rare malignancy accounting for less than 5% of all the gastrointestinal tract cancers. However, only limited data and expert guidelines are available for this entity. As a result, treatment concepts are predominantly derived from colorectal cancer., Methods: To substantiate data on the course of disease, diagnosis and treatment of SBA, we performed a population-based analysis from a Bavarian population of 2.2 million people., Results: We identified 223 patients with SBA. Mean age at diagnosis was 67.8 years and patients were diagnosed rather late (34.5% UICC stage IV). Largest proportion of these patients were diagnosed with adenocarcinoma of the duodenum (132 patients, 59.2%) and most patients were diagnosed with late stage cancer, stage IV (70 patients, 31.4%). With respect to treatment, most patients underwent primary surgery (187 patients, 84.6%). Systemic therapy seemed to have an impact in UICC stage IV patients but not in UICC stage IIB or III. The 5-year survival rate was 29.0%. This was significantly less compared to colon cancer in the same cohort, which was 50.0%. Furthermore, median survival of patients with small bowel cancer was only 2.0 years (95% CI 1.4-2.5) compared to 4.9 years (95% CI 4.8-5.1) of patients with colon cancer., Conclusion: SBA showed a distinct epidemiology compared to colon cancer. Thus, data acquisition particularly on systemic treatment are paramount, with the objective to complement the available guidelines., (© 2022. The Author(s).)

Background: Angiosarcoma is a highly malignant soft-tissue sarcoma derived from vascular endothelial cells that mainly occurs in the skin and subcutaneous tissues. Small-intestinal angiosarcomas are rare, and the prognosis is poor., Case Summary: We reported a case of primary multifocal ileal angiosarcoma and analyze previously reported cases to improve our understanding of small intestinal angiosarcoma. Small intestinal angiosarcoma is more common in elderly and male patients. Gastrointestinal bleeding, anemia, abdominal pain, weakness, and weight loss were the common symptoms. CD31, CD34, factor VIII-related antigen, ETS-related gene, friend leukemia integration 1, and von Willebrand factor are valuable immunohistochemical markers for the diagnosis of small-intestinal angiosarcoma. Small-intestinal angiosarcoma most commonly occurs in the jejunum, followed by the ileum and duodenum. Radiation and toxicant exposure are risk factors for angiosarcoma. After a definite diagnosis, the mean and median survival time was 8 mo and 3 mo, respectively. Kaplan-Meier survival analysis showed that age, infiltration depth, chemotherapy, and the number of small intestinal segments invaded by tumor lesions were prognostic factors for small intestinal angiosarcoma. Multivariate Cox regression analysis showed that chemotherapy and surgery significantly improved patient prognosis., Conclusion: Angiosarcoma should be considered for unexplained melena and abdominal pain, especially in older men and patients with a history of radiation exposure. Prompt treatment, including surgery and adjuvant chemotherapy, is essential to prolonging patient survival., Competing Interests: Conflict-of-interest statement: The authors declare that they have no conflict of interest to disclose., (©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.)

Purpose: The number of  neuroendocrine tumors (NETs) is gradually increasing worldwide, and those located in the small intestine (siNETs) are the most common. As some biological and clinical characteristics of tumors of the jejunum and the ileum differ, there is a need to assess the prognosis of individuals with siNETs of the jejunum and ileum separately. We generated a predictive nomogram by assessing individuals with siNETs from the Surveillance, Epidemiology, and End Results (SEER) database., Methods: We used univariate Cox regression analysis to determine both the overall survival (OS) and the cancer-specific survival (CSS) of 2501 patients with a pathological confirmation of siNETs of the jejunum and ileum. To predict 3-, 5-, and 10-year OS of siNETs, a nomogram was generated based on a training cohort and validated with an external cohort. Accuracy and clinical practicability were evaluated separately by Harrell's C-indices, calibration plots, and decision curves. The correlation was examined between dissected lymph nodes and positive lymph nodes., Results: Dissection of 7 or more lymph nodes significantly improved patient OS and was found to be a protective factor for patients with siNETs. In Cox regression analyses, age, primary site, tumor size, N stage, M stage, and regional lymph node examination were significant predictors in the nomogram. A significant positive correlation was found between dissected lymph nodes and positive lymph nodes., Conclusions: Patients with 7 or more dissected lymph nodes showed an accurate tumor stage and a better prognosis. Our nomogram accurately predicted the OS of patients with siNETs., (© 2022. The Society for Surgery of the Alimentary Tract.)

Purpose: The last 2 decades has witnessed efforts towards standardization of surgery for small bowel cancers. The proposed recent guidelines/recommendations pertaining to choice of procedure and extent of lymphadenectomy are based on analysis of data from high volume centres of excellence. We evaluated whether these recently proposed oncologic recommendations can be replicated in the setting of single centre/team., Methods: This was a retrospective analysis of consecutive adult patients (age ≥ 18 years) who underwent surgery for tumours of small intestine (duodenum, jejunum, and ileum) by the same team of surgeons from 01/01/2010 to 12/31/2019. The procedure performed and lymph nodes harvested during pathologic examination were compared with recent recommendations., Results: Of the 32 patients (20 males and 12 females), mean age was 52.4 (range 31-77) years. Twenty-nine (90.6%) patients underwent surgery for small bowel cancers. Duodenum was the most common site, while NET was the commonest cancer. Whipple's procedure was performed for tumours of II part of duodenum, while for the rest, segmental resection was performed. The median number of lymph nodes examined for duodenal adenocarcinoma and NET was 14 and 9, respectively. For jejunal/ileal adenocarcinoma, median lymph node number examined was 11., Conclusion: Our study shows that these recently proposed standards for surgery of small bowel cancers are achievable if basic principles of oncologic surgery are followed., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

Background: The efficacy and safety of bevacizumab-containing chemotherapy for patients with metastatic duodenal and jejunal adenocarcinoma (mDJA) are unclear. The present study aimed to evaluate the efficacy of bevacizumab and to explore immunohistochemical markers that can predict the efficacy of bevacizumab for patients with mDJA., Methods: This multicentre study included patients with histologically confirmed small bowel adenocarcinoma who received palliative chemotherapy from 2008 to 2017 at 15 hospitals. Immunostaining was performed for vascular endothelial growth factor-A (VEGF-A), TP53, Ki67, β-catenin, CD10, MUC2, MUC5AC, MUC6, and mismatch repair proteins., Results: A total of 74 patients were enrolled, including 65 patients with mDJA and 9 with metastatic ileal adenocarcinoma. Patients with mDJA who received platinum-based chemotherapy with bevacizumab as first-line treatment tended to have a longer progression-free survival and overall survival than those treated without bevacizumab (P = 0.075 and 0.077, respectively). Multivariate analysis extracted high VEGF-A expression as a factor prolonging progression-free survival (hazard ratio: 0.52, 95% confidence interval: 0.30-0.91). In mDJA patients with high VEGF-A expression, those who received platinum-based chemotherapy with bevacizumab as a first-line treatment had significantly longer progression-free survival and tended to have longer overall survival than those treated without bevacizumab (P = 0.025 and P = 0.056, respectively), whereas no differences were observed in mDJA patients with low VEGF-A expression., Conclusion: Immunohistochemical expression of VEGF-A is a potentially useful biomarker for predicting the efficacy of bevacizumab-containing chemotherapy for patients with mDJA., (© 2021. The Author(s).)

Purpose: This aim of this study was to provide a comprehensive understanding of the clinical characteristics, treatment, and prognosis of patients with small bowel adenocarcinoma (SBA), mucinous small bowel adenocarcinoma (MSBA), and signet ring cell carcinoma of the small bowel (SRCSB)., Methods: Information on patients with SBA, MSBA, and SRCSB (2004-2015) was obtained from the Surveillance, Epidemiology and End Results (SEER) database. Cox proportional hazards models and Kaplan-Meier curves were used for the survival analyses. Propensity-score matching (PSM) was implemented to determine the differences among these tumors., Results: In all, 3697 patients with SBA (n = 3196), MSBA (n = 325) and SRCSB (n = 176) were ultimately eligible for this study. Poor differentiation, local invasion, and lymph node metastasis were more likely to be observed in SRCSB than in SBA and MSBA. Surgery was the most common treatment modality in all groups. The prognosis of SBA was similar to that of MSBA, but better than that of SRCSB in both unmatched and matched cohorts. M stage, surgery, and chemotherapy were identified as independent predictors of survival in all patients. Surgery and chemotherapy could significantly improve outcomes in all groups before and after PSM. Radiotherapy was associated with a survival benefit in patients with SBA, but this trend was not maintained after PSM. Survival advantages of SBA and MSBA were remarkable in the stratified analysis of surgery after PSM., Conclusion: Patients with SRCSB had the worst prognosis among all histological types examined. However, surgery and chemotherapy could improve patients survival, regardless of histological type., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2021 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

The tumor microenvironment (TME) has become an important area of investigation with respect to improving prognosis in malignancies. Here we evaluated TME prognostic risk in small intestinal adenocarcinomas based on histologic assessment of tumor budding at the peritumoral-invasive front (pTB) and stromal tumor-infiltrating lymphocytes (sTILs). pTB and sTILs were analyzed in 230 surgically resected small intestinal adenocarcinomas, as recommended by the International Tumor Budding Consensus Conference (ITBCC) and the International TILs Working Group (ITWG). On the basis of high levels of pTB count (≥10) and sTIL density (≥20%), we combined pTB and sTIL to produce a collective TME-based prognostic risk index: low-risk (pTBLow/sTILHigh; n=39, 17.0%), intermediate-risk (pTBLow/sTILLow or pTBHigh/sTILHigh; n=99, 43.0%), and high-risk groups (pTBHigh/sTILLow; n=92, 40.0%). TME risk index provided better prognostic stratification than the individual pTB and sTIL (14.9 vs. 6.7 vs. 10.3). Tumors with higher TME prognostic risk were associated with an infiltrative growth pattern and nonintestinal immunophenotype (both P=0.001), pancreatic invasion (P=0.010), lymphovascular (P<0.001) or perineural invasion (P=0.006), higher T-category (P<0.001), N-category (P=0.004), and stage grouping (P=0.002), and KRAS mutation (P=0.008). In multivariate analysis, higher TME prognostic risk index (P<0.001), distal tumor location and nonintestinal immunophenotype (both P=0.001), higher N-category (P<0.001), and microsatellite stable (P=0.015) were worse-independent prognosticators. TME prognostic risk index consistently stratified patient survival regardless of tumor location (P<0.001 in proximal; P=0.002 in distal), stages (P<0.001 in lower stages I to II; P=0.028 in stage III), and DNA mismatch repair gene status (P<0.001 in microsatellite stable; P=0.001 in microsatellite instability). TME risk index is a powerful prognostic predictor for risk stratification of patients with small intestinal adenocarcinoma., Competing Interests: Conflicts of Interest and Source of Funding: Supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1D1A1B03031817, awarded to S.-Y.J.). The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Small-bowel adenocarcinoma (SBA) is rare, and no standard of care exists for metastatic disease beyond first-line FOLFOX/CAPOX. SBA has higher rates of microsatellite instability (MSI-H) and T-lymphocyte infiltration than other gastrointestinal cancers. We hypothesize that pembrolizumab, a PD-1 inhibitor, will induce antitumor response., Patients and Methods: Patients with previously treated advanced SBA received pembrolizumab 200 mg i.v. every 3 weeks until disease progression (PD), toxicity, or 35 doses maximum. Primary endpoint was confirmed overall response rate (ORR) with secondary progression-free survival (PFS), overall survival (OS), and toxicity assessment endpoints. Outcomes were stratified by tumor location, microsatellite stability (MSS) or instability (MSI-H), and PD-L1 level., Results: Forty patients were treated for a median duration of four cycles (range, 1-35). All patients are off study treatment due to PD (75%), death (10%), 35 cycles completed (8%), refusal (3%), and adverse effects (AEs, 5%). Three confirmed partial responses [PRs; 8%; 95% confidence interval (CI), 2-20] did not meet predefined success criteria of ORR 30%. Median OS (7.1 months; 95% CI, 5.1-17.1) and median PFS (2.8 months; 95% CI, 2.7-4.2) were similar across primary tumor sites. One confirmed PR (3%) was seen in patients with low MSS/MSI tumors and correlated with high tumor mutation burden (TMB). Fifty percent of patients with MSI-H tumors achieved PR and remain alive without progression. Twenty-five patients (63%) had grade ≥3 AEs and 11 patients (28%) had grade 4/5 AEs., Conclusions: In the largest study of SBA to date, pembrolizumab did not induce the hypothesized response rate; however, we did identify responses in key biomarker-selected cohorts., (©2021 American Association for Cancer Research.)

Purpose of Review: Small intestinal neuroendocrine neoplasms (siNENs) are slowly growing tumours with a low malignant potential. However, more than half of the patients present with distant metastases (stage IV) and nearly all with locoregional lymph node (LN) metastases at the time of surgery. The value of locoregional treatment is discussed controversially., Recent Findings: In stage I to III disease, locoregional surgery was currently shown to be curative prolonging survival. In stage IV disease, surgery may prolong survival in selected patients with the chance to cure locoregional disease besides radical/debulking liver surgery. It may improve the quality of life and may prevent severe local complications resulting in a state of chronic malnutrition and severe intestinal ischaemia or bowel obstruction. Locoregional tumour resection offers the opportunity to be curative or to focus therapeutically on liver metastasis, facilitating various other therapeutic modalities. Risks and benefits of the surgical intervention need to be balanced individually.

The current understanding of clinicopathological features and genomic variants of small-bowel cancer is limited, in part due to the rarity of the disease. However, understanding of these factors is necessary for the development of novel therapeutic agents for small-bowel cancer. Thus, we aimed to identify the clinicopathological features and genomic variants associated with its prognosis and recurrence. We retrospectively examined 24 consecutive patients with primary small-bowel cancer surgically treated between May 2005 and August 2018 and collected 29 tumor specimens. The 29 lesions were subjected to mismatch repair status evaluation, using immunohistochemistry (IHC), and targeted genomic sequencing, after which they were analyzed using a panel of 90 cancer-related genes. IHC revealed that 45% (13/29) of the lesions exhibited deficient mismatch repair. The most common genomic variants in small-bowel cancers were in TP53 (48%, 13/27), followed by KRAS (44%, 12/27), ARID1A (33%, 9/27), PIK3CA (26%, 7/27), APC (26%, 7/27), and SMAD4, NOTCH3, CREBBP, PTCH1, and EP300 (22%, 6/27 each). Overall survival and disease-specific survival of patients with tumor mutational burden (TMB) ≥10 mutations/Mb (n = 17) were significantly better than those of patients with TMB <10 mutations/Mb (n = 6). Additionally, patients with a mutant SMAD4 had poorer recurrence-free survival than those with wild-type SMAD4. Our results suggested that TMB and SMAD4 mutations were associated with the prognosis of small-bowel cancer patients. Thus, cancer genomic analysis could be useful in the search for biomarkers of prognosis prediction in small-bowel cancers., Competing Interests: The authors have declared that no competing interests exist.

Pancreatic heterotopia is a well-described entity occurring at multiple abdominal sites, most commonly the stomach and small intestine. They can develop similar disease processes as the pancreas ranging from acute pancreatitis, cyst formation, or neoplasms, most commonly ductal adenocarcinoma. Neuroendocrine tumors (NETs) arising in pancreatic heterotopias are exceedingly rare with only 3 prior published cases. In this article, we describe the first reported case of a NET arising in a jejunal pancreatic heterotopia in a 59-year-old woman presenting with abdominal pain and diarrhea. The submucosal tumor was composed of a well-differentiated NET (World Health Organization grade 1) directly intermixed with a heterotopic pancreas consisting of acinar cells, islet cells, and ducts. This case illustrates that NETs can occur in association with pancreatic heterotopias at any site. Also, the importance for pathologists to recognize that pancreatic heterotopias can give rise to a variety of neoplasms and is not limited to ductal adenocarcinoma.

Background: Small intestinal cancer is less common than some other gastrointestinal malignancies. Tumours of different histological types and anatomical sites of origin have therefore often been described together. The aim of this study was to investigate the epidemiology for each of the four main subtypes: duodenal adenocarcinoma (D-AC), duodenal neuroendocrine tumour (D-NET), jejunoileal adenocarcinoma (J/I-AC), and jejunoileal neuroendocrine tumour (J/I-NET)., Methods: All patients with small intestinal cancer diagnosed between 1960 and 2015 were identified from the Swedish Cancer Register. The age-adjusted incidence rate with incidence rate ratios, as well as overall (OS) and net (NS) survival, were determined and temporal trends were analysed., Results: The incidence rate was highest for J/I-NET, with 9.98 clinical diagnoses per million in 2010-2015. Clinical diagnosis of D-AC increased more than 10-fold and surpassed J/I-AC as the second most common subtype. D-NET was by far the least common subtype. Diagnosis at autopsy became less common over time, whereas clinical diagnoses increased significantly for all four subtypes. All subtypes except J/I-AC affected men more often than women. The age distribution was similar between subtypes, although patients with adenocarcinomas were slightly older. Survival was generally much better for patients with NET than for those with adenocarcinoma. Both OS and NS showed a negative association with advancing age. Survival improved only for J/I-NET from a 5-year NS of 0.69 in the 1960s to 0.81 in 2010-2015., Conclusion: The incidence of small intestinal cancer is increasing, particularly for D-AC and in the elderly. Survival of patients with small intestinal cancer has improved only for J/I-NET over the last decades., (© The Author(s) 2021. Published by Oxford University Press on behalf of BJS Society Ltd.)

Introduction: Small bowel is an uncommon site for primary neoplasm in the gastrointestinal tract. Traditionally, duodenum has been combined with jejunum and ileum in analysing the presentation and management of these tumors. Given the different presentation pattern, diagnostic difficulties and anatomical considerations, jejunal tumors may differ from duodenal tumors., Methodology: Retrospective analysis of a prospectively maintained database of patients with histology proven jejunal tumors was done. Clinico-radiological characters, histological findings, surgical procedures and the outcomes in these patients were studied., Results: Sixteen patients were included in the study. Median age at presentation was 42 years (26-76 years) and majority were males (n = 11, 68.8%). Seven (43.7%) patients presented with emergencies. Endoscopic tissue diagnosis could be obtained in 5 (31.3%) patients. Histology of tumors were adenocarcinoma, gastrointestinal stromal tumor and lymphoma in 6 (37.5%), 5 (31.3%) and 3 (18.8%) respectively. Sarcoma (myxofibroma) and metastasis (urothelial origin) were present in one patient each. Two patients with adenocarcinoma had neoadjuvant chemotherapy. Curative resection was feasible in 14 patients. Resection of tumor-bearing segment with anastomosis was performed in 9 patients. Among these, 5 had duodenojejunostomy. One patient had resection and double-barrel jejunostomy. One patient with jejunal GIST had sleeve resection. Multi-visceral resection was performed in 3 patients. There were no mortality and median postoperative hospital stay was 11 days (range 7-33 days)., Conclusion: Histology spectrum of jejunal tumors are distinct. Difficulty in obtaining preoperative tissue diagnosis of these lesions need to be addressed by improved endoscopic and image-directed biopsy techniques.

Background: Proximal (duodenal) small bowel adenocarcinomas have a worse prognosis than distal (jejuno-ileal) tumors, but differences in patient, tumor, and treatment factors between locations remain unclear., Methods: Patients in the National Cancer Database with surgically resected pathologic stage I-IV small bowel adenocarcinomas between 2004 and 2015 were analyzed. Clinical stage IV patients were excluded., Results: Proximal tumors (n = 3767) were more likely to be higher grade (OR 1.52, CI 1.22-1.85 for moderately; OR 1.83, CI 1.49-2.33 for poorly differentiated, P < 0.01 for both) and have positive lymph nodes (OR 2.04, CI 1.30-3.23, P < 0.01), while distal tumors (n = 3252) were likely to be larger (OR 1.31, CI 1.07-1.60 for size > 5 cm, P < 0.01). Proximal tumors were associated with worse overall survival (OS) and stage-specific survival compared with distal tumors (all P < 0.01). Cox regression analysis of the entire cohort showed worse survival with community versus academic cancer programs, higher comorbidity scores, pathologic stage IV, poorly differentiated histology, positive nodal or margin status, and proximal location, while female gender, larger tumor size, and chemotherapy predicted better survival. On separate Cox regression analyses of each location, neoadjuvant chemotherapy was associated with better OS in the proximal cohort (HR 0.70, CI 0.55-0.88, P < 0.01), while adjuvant chemotherapy was associated with better OS for both proximal (HR 0.49, CI 0.42-0.57, P < 0.01) and distal tumors (HR 0.68, CI 0.57-0.81, P < 0.01)., Conclusions: Proximal small bowel adenocarcinomas are associated with worse overall and stage-specific survival. This may be due to tumor biologic differences as proximal tumors were more likely to have higher grade. Future studies should further investigate differences between proximal and distal tumors to guide targeted treatment algorithms., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Inflammatory fibroid polyps (IFP) are rare type of benign tumours found in the gastrointestinal tract. IFP´s are in most cases small in size and without symptoms but can cause intussuception and haemorrhage. We present a case of a 25 year old female who presented with abdominal pain and symptoms and signs of anemia, hemoglobin was 36 g/L upon arrival. Further workup revealed a large tumor in the small intestine. The patient underwent a partial resection of the proximal jejunum. Pathology of the specimen showed inflammatory fibroid polyp.

Small bowel adenocarcinomas are rare. There is no definite consensus as to whether they should be treated in a manner similar to gastric or to colon cancer. We report the case of a young woman with a primary jejunal adenocarcinoma, bilateral ovary metastases, and peritoneal dissemination. First- and second-line chemotherapy for the gastric cancer failed. She was then treated with the immune checkpoint inhibitor nivolumab and had temporary improvement in her condition. To the best of our knowledge, this is the first case wherein nivolumab has been used to treat small bowel adenocarcinoma.

Basic and clinical studies on small bowel adenocarcinoma (SBA) are limited due to the rare nature of this cancer. We established a patient-derived xenograft (PDX) model from the tumor tissue of an advanced SBA patient with liver and peritoneal metastasis, and a cell line from the PDX. In the PDX model, compared to the control group, 5-fluorouracil (5-FU) treatment resulted in statistically significant tumor growth inhibition (TGI), while oxaliplatin (OHP) and irinotecan had no significant inhibitory effects. In combination with 5-FU, OHP showed the highest rate of TGI. The IC 50 for OHP was significantly lower than those for paclitaxel, gemcitabine, and trifluorothymidine in the PDX-derived cell line when compared to in HT29, a colon cancer cell line. Genetic analysis of the patient tumor, PDX tumor, and the cell line demonstrated consistency in the microsatellite status and mutations in TP53, APC, HRAS, CSF1R, FGFR3, FLT3, PDGFRA, and RET genes. However, the PDX tumor alone had additional mutations, indicating that the PDX-derived cell line may support the unstable genetic status of the PDX. Our findings confirmed the effectiveness of the combination of OHP and 5-FU, which is a common treatment for advanced SBA and advanced colorectal cancer, in a preclinical model. This preclinical model of SBA can help in further understanding the biology of SBA., (© 2020 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Background: Small bowel adenocarcinoma (SBA) is a rare malignancy that primarily occurs in the duodenum. Multiple synchronous SBA is unique rare and difficult to diagnose due to non-specific disease presentation. Protocols to identify multiple synchronous SBA during early disease stages are urgently required., Case Presentation: An elderly man experienced left lower abdominal pain and melena for 3 months. Abdominal CT showed thickening of the multiple segmental small intestinal walls. As the patient had pulmonary tuberculosis simultaneously, he was misdiagnosis as intestinal tuberculosis and received anti-spasm therapy. The treatment delayed radical resection surgery and the patient underwent palliative segmental resection of the jejunum after 4 months due to intestinal obstruction. Resected specimens showed multiple synchronous SBA (five tumors). The patient accepted chemotherapy postoperatively. Six months postoperatively, the patient died of brain metastasis., Conclusions: We highlight how multiple synchronous SBA is rare and easily misdiagnosed. We should rule out multiple synchronous SBA when diagnosing intestinal diseases (e.g. inflammatory bowel disease, IBS). Intestinal tuberculosis may also be one of the risk factors for multiple synchronous SBA. High-risk patients should be assessed for known tumor makers, and receive gastroscopy, enteroscopy or capsule endoscopy. Doctors should obtain the pathology under endoscopy to the greatest possible degree. For suspected patients, laparotomy should be performed.

Background: Small bowel adenocarcinoma (SBA) is a rare disease. Current recommendations are largely extrapolated from the colorectal literature. For node-negative (N -ve) cases, optimally stratifying cases into high or low risk, may help define optimal management. The objective of this analysis was to determine the importance of lymph node sampling for prognostication and to define what number of lymph nodes sampled is adequate., Methods: Cases of non-metastatic SBA with complete staging, pathologic, and demographic information were selected from the SEER database and SAS 9.4 software was used. Variables included age, gender, race, grade, TNM staging, and number of lymph nodes were examined. Comparisons were made between N -ve and N +ve cases. Survival analysis using N -ve cases was performed to characterize the impact of nodal sampling on survival and to determine which nodal cut-offs best predict survival., Results: A total of 523 cases from 2004 to 2014 were included in this analysis. Statistically significant differences identified included the median number of nodes sampled between the N -ve and N +ve groups, and the distribution of T stage and grade. Survival analysis in the N -ve cases demonstrated that the strongest predictor of survival was sampling of 16 or more lymph nodes., Conclusion: In this analysis, lymph node sampling was shown to be the most important pathologic predictor of survival in cases of N -ve SBA. Replicating these findings in a secondary dataset and determining whether a clinical benefit of adjuvant chemotherapy exists for SBA patients with inadequate sampling are both important next steps.

Background: Small bowel adenocarcinoma (SBA) is a dreadful disease. Patient prognosis is limited due to late presentation and ineffective chemotherapy. PD-1/PD-L1 checkpoint immunotherapy is regarded as a promising approach in several cancer entities. The association of PD-1/PD-L1 expression and its impact on patient prognosis with SBA is unclear. Material and methods: Seventy-five consecutive patients who underwent surgery for SBA were retrospectively analyzed and stained for PD-L1 expression in the tumour or the stroma. Analysis of mismatch repair genes was performed to determine microsatellite status. Kaplan-Meier estimate was used to analyze patient survival. Univariate and multivariable Cox regression-analyses were used to assess the impact of PD-L1 expression and microsatellite status on patient survival. Results: PD-L1 was weakly upregulated within the tumour or the stroma and associated with prolonged survival ( p  = .0071 and p  = .0472, respectively). Fifty-one tumours (68%) revealed microsatellite stability (MSS) and 24 tumours (32%) were microsatellite instable (MSI) without correlating with patient survival ( p  = .611). Neither PD-L1 expression in the tumour nor in the stroma was identified as an independent risk factor influencing survival ( p  = .572 and p  = .3055). Conclusion: Although PD-L1 expression is associated with prolonged survival, it was not identified as an independent prognostic marker. Microsatellite status did not influence long-term survival.

Competing Interests: Competing interests: None declared.

Rationale: Hemolymphangioma is a benign tumor comprised of the newly-formed lymph spaces and blood vessels, which can usually be found in the head and neck of the affected children. There are few reports regarding cases with hemolymphangioma in small intestine, spleen, esophagus, and other organs., Patient Concerns: Herein, a 55-year-old woman was presented in this study, she had complained of discomfort in the right upper abdomen for 2 months, and was discovered with a space-occupying lesion in proximal jejunum on computed tomography (CT). Eventually, the lesions were confirmed through double-balloon enteroscopy (DBE) to be located in the jejunum 60 cm away from the Treitz ligament., Diagnose: Subsequently, the small intestine was partially resected, and postoperative pathology had confirmed the diagnosis of small intestinal hemolymphangioma., Interventions: Excisional surgery of the lesion was planned. On surgery, the lesions were discovered to be about 33 cm to 22 cm when engorged the superficial vessels. No enlarged lymph nodes were seen at the root of the mesentery, and no obvious lesion was observed in the remaining small intestine., Outcomes: Follow-up for 6 months showed no recurrence., Lessons: Hemolymphangioma lacks typical clinical symptoms, and the correct preoperative diagnosis of hemolymphangioma remains challenging. Due to the increasing use of endoscopic diagnostic techniques, it is expected that hemolymphangioma in gastrointestinal tract may be detected and endoluminal located before surgery more feasibly. This case report aimed to highlight the contributions of CT and DBE to an accurate preoperative diagnosis and surgical strategy planning.

Gastrointestinal stromal tumors are the most common mesenchymal tumors of the gastrointestinal tract. They are generally considered as solitary tumors. Here we report the case of a 66-year-old man with familial history of digestive cancers, admitted after a 2-months history of gastrointestinal bleeding. Colonoscopy showed a circumferential ulcerated tumor of the sigmoid which was a well differentiated adenocarcinoma on biopsy. Computerized tomography showed only the lesion of the sigmoid. The patient underwent a left colectomy followed by immediate end-to-end anastomosis. Per-operatively, jejunal mass was discovered and a jejunal segmentectomy was performed. Pathologic examination revealed a colic adenocarcinoma pT2N0M0 associated with a low risk stromal tumor of the jejunum CD117+ and DOG-1+. No adjuvant therapy was given. After 64 months of follow-up, the patient showed no evidence of recurrence. Clinicians should be aware of the coexistence of malignancies and carry careful investigations for accurate diagnosis and better patients' prognosis., Competing Interests: The authors declare no competing interest., (© Refeno Valéry et al.)

Rationale: Patients with gastrointestinal stromal tumors (GISTs) are often found to have liver metastases at their 1st presentation. Most patients need preoperative treatment to reduce the size of the liver metastases to increase the possibility of surgical resection. Currently, imatinib mesylate is the drug of 1st choice for preoperative treatment and sunitinib malate (SM) is seldom used. Here we report a case of GIST with liver metastases where SM was used as a preoperative treatment., Patient Concerns: A 56-year-old worker presented with intermittent abdominal pain and eating difficulties., Diagnoses: An enhanced computed tomography scan showed a 15 × 15 × 10 cm malignant mass in the upper abdomen, and 2 metastases (15.1 × 13.1 cm and 14.8 × 8.8 cm) in the liver. The postcaval and middle hepatic veins were compressed by the liver metastases, making radical resection very difficult., Interventions: First the primary tumor in the jejunum was resected, and then SM was used as a preoperative treatment to reduce the size of the liver metastases to improve the possibility of surgical resection., Outcomes: Both liver metastases regressed considerably in size and it was then possible to perform a radical resection., Lessons: The SM has the potential to be used as preoperative therapy for GIST with large liver metastases. This method provides a new option for the preoperative treatment of GIST with liver metastases.

Background: Small bowel adenocarcinomas (SBAs) are rare tumors. Management of SBA is extrapolated from colorectal cancer treatments. Recent evidence suggests that the biology and molecular features of SBA differ from colorectal cancer. The aim of this study was to evaluate the management and outcome of SBA patients. PATIENTS AND METHODS: The National Cancer Data Base (NCDB) was queried for patients with SBA between 2004 and 2013 using ICD-O-3 histology code 8140/3 and topography codes C17.0, C17.1, C17.2, C17.8, and C17.9. Univariate and multivariate survival analyses were conducted to analyze the association between SBA location and overall survival (OS) stratified by stage. Treatment outcomes of surgery, radiation, and systemic therapy were compared., Results: A total of 7954 SBA patients were identified; duodenum (D) 4607 (57.9%), jejunum (J) 1241 (15.6%), ileum (I) 857 (10.8%), and unspecified 1249 (15.7%). A total of 53.6% patients were male, and 76.6% white. Median age was 66 years. D mostly presented as stage IV disease (37.6%), J as stage II (34.5%) and IV disease (33.8%), and I as stage II (32.2%) and III (30.3%) disease (P < .001). Grade distribution was similar among D, J, and I; the majority were moderately differentiated (40.8%-55.0%), followed by poorly differentiated (30.9%-35.8%) and well differentiated (6.0%-12.4%) (P < .001). D underwent surgery (50.2%) less often than J (90.8%) and I (94.5%) (P < .001). Adjuvant radiation was provided in 8.5% of D, 2.6% of J, and 2.1% of I (P < .001). Adjuvant chemotherapy was provided in 21.9% of D, 50.2% of J, and 42.0% of I (P < .001). The rate of adjuvant chemotherapy was the highest in patients with stage III SBA, and was as follows: D (43.4%), J (65.4%), and I (63.6%) (P < .001). In univariate and multivariate analyses of all patients, adjuvant chemotherapy was associated with improved OS in stage II-III SBA patients. J had the best 5-year OS rate (42.0%; 95% confidence interval, 38.8-45.1, P < .001), and D had the worst (23.0%; 95% confidence interval, 21.6-24.2, P < .001). In multivariate analysis stratified by stage, chemotherapy was associated with improved OS in patients with stage II-IV SBA., Conclusion: Most SBA patients present with stage IV disease. D underwent surgery less often than J and I. Stage II and III D received adjuvant chemotherapy less often compared to stage II and III J and I. Adjuvant chemotherapy was associated with improved OS in patients with stage II-III disease. J had the best 5-year OS rate, and D had the worst., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Mesenteric lymphangiomas are relatively rare, with clinical symptoms ranging from an asymptomatic presentation to an acute abdomen. The natural history and biological behaviour of this entity can range from slow indolent lesions to aggressive tumours with a risk of malignant transformation. Spontaneous regression of a mesenteric lymphangioma is rare. We herein report a case of a jejunal mesenteric lymphangioma that was initially detected incidentally in an asymptomatic patient with a subsequent sudden increase in size with resulting surrounding mass effect after 9 months and a spontaneous partial regression at surgical resection. Our case is the first reported case which outlines a period in the natural history and evolution of microcystic mesenteric lymphangioma, illustrating the sudden enlargement likely attributable to spontaneous and self-limiting haemorrhage and subsequent partial regression at surgical resection. We thenceforth propose a possible management algorithm for adult patients with mesenteric lymphangiomas., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a provisional entity in the 2017 World Health Organization classifications. To further elucidate the clinicopathologic features of this new disease, we carried out a retrospective, multicenter analysis of 42 patients with MEITL. The median age of the patients was 59 years (range, 20-84 years), and 27 patients (64 %) were male. Thirty-two patients (76 %) were Ann-Arbor stages I-II and 28 (67 %) were Lugano stages I-II 1&2 . The most frequent site of involvement was the jejunum (N = 21). Most cases expressed CD8 (79 %) and CD56 (95 %) and did not express CD30 (5 %) or EBER (0 %). The median progression-free survival was 6.9 months (95 % CI 4.3-9.6); the median OS was 14.8 months (2.4-27.2). Thirty-two patients (76 %) underwent surgery and 37 (88 %) received chemotherapy. A complete response (CR) rate was 38 %. Sixteen patients had undergone autologous stem cell transplantation (ASCT). Relapse or progression was documented in 24 cases, most frequently in the primary site (N = 23). Four cases showed central nervous system relapse. Age over 55 years, poor performance scale, advanced Lugano stage (II E -IV), not achieving CR, and not receiving ASCT were associated with inferior OS. While the optimal management of MEITL remains undetermined, achieving CR and consolidative ASCT seem essential. As CHOP might be insufficient for achieving CR, more efficient combinations should be investigated. Additionally, considering the frequent local failure and CNS relapse, novel therapeutic approaches are required to improve survival.