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UTX/KDM6A, a histone H3K27 demethylase and a key component of the COMPASS complex, is frequently lost or mutated in cancer; however, its tumor suppressor function remains largely uncharacterized in multiple myeloma (MM). Here, we show that the conditional deletion of the X-linked Utx in germinal center (GC) derived cells collaborates with the activating BrafV600E mutation and promotes induction of lethal GC/post-GC B cell malignancies with MM-like plasma cell neoplasms being the most frequent. Mice that developed MM-like neoplasms showed expansion of clonal plasma cells in the bone marrow and extramedullary organs, serum M proteins, and anemia. Add-back of either wild-type UTX or a series of mutants revealed that cIDR domain, that forms phase-separated liquid condensates, is largely responsible for the catalytic activity-independent tumor suppressor function of UTX in MM cells. Utx loss in concert with BrafV600E only slightly induced MM-like profiles of transcriptome, chromatin accessibility, and H3K27 acetylation, however, it allowed plasma cells to gradually undergo full transformation through activation of transcriptional networks specific to MM that induce high levels of Myc expression. Our results reveal a tumor suppressor function of UTX in MM and implicate its insufficiency in the transcriptional reprogramming of plasma cells in the pathogenesis of MM.

Next-generation sequencing of oral squamous cell carcinoma (OSCC) has revealed TP53 as the most frequently mutated gene in OSCC mutually exclusive with human papillomavirus infection. Oral epithelial dysplasia (OED) is defined as a precancerous lesion of OSCC by the current World Health Organization (WHO) classification; therefore, it is assumed that TP53 mutations occur in early precancerous conditions such as OED. Here, we conducted an integrated analysis of TP53, including whole coding sequencing of TP53, FISH analysis of the 17p13.1 locus, and immunohistochemical analysis for p53 (p53-IHC), in 40 OED cases. We detected 20 mutations in 16 (40%) OED cases, and four cases, each harbored two mutations. FISH analysis revealed six of 24 cases (25%) had a deletion on 17p13.1, and four cases had concurrent TP53 mutations and 17p13.1 deletion (2-hit). Also, the increased frequency of TP53 mutations in higher degrees of OED implies acquisition of the mutation is a major event toward OSCC. p53-IHC revealed that overall cases could be categorized into four patterns that correlate well with the mutational status of TP53. Especially, two patterns, broad p53 expression type (pattern HI) and p53 null type (pattern LS), strongly correlated with a missense mutation and nonsense mutation, respectively. Furthermore, seven of the 40 cases progressed to SCC, and six of these seven cases presented pattern HI or LS. Therefore, patterns HI and LS have a high risk for malignant transformation if excisional treatment is not performed irrespective of the dysplasia grade. Although the current WHO classification mainly focuses on morphological criteria for the diagnosis of OED, interobserver discrepancy appears in some instances of the OED diagnosis. Our immunohistochemical analysis supports a more accurate pathological diagnosis for OED in cases of low dysplastic changes or of differential diagnosis with non-dysplastic lesions.

Background: Laparoscopic surgery for malignant tumours occasionally results in recurrence at the trocar insertion site or port-site metastasis (PSM). We report on a patient requiring emergency laparoscopic surgery for an ovarian tumour with a review of the relevant literature. Case Report: A 42-year-old woman developed sudden abdominal pain and underwent laparoscopic right adnexectomy because of a suspected ovarian cystic tumour rupture. The postoperative histological diagnosis was a mucinous borderline ovarian tumour; however, an undifferentiated carcinoma was detected at the port site eight months after the initial surgery. The histopathological diagnosis of the abdominal wall tumour at the port site differed from intraoperative pathological findings, which was contradictory to PSM definition. Postoperatively, she received three systemic chemotherapy courses but died consequent to tumour metastasis. Conclusion: This is an atypical PSM case with histopathological differences from the initial tumour. Careful preoperative diagnosis and intraoperative attention are essential in such cases.

The prevalence of Lynch syndrome (LS)-associated DNA mismatch repair (MMR)-deficient bladder cancer (BC) has scarcely been investigated. Immunohistochemistry for four MMR proteins (MLH1, MSH2, MSH6, and PMS2) was performed in formalin-fixed paraffin-embedded (FFPE) sections prepared from the resected specimens of 618 consecutive newly diagnosed BC cases. Genetic/epigenetic analyses were performed in patients displaying the loss of any MMR proteins in the tumor. Of the 618 patients, 9 (1.5%) showed the loss of MMR protein expression via immunohistochemistry; specifically, 3, 3, 2, and 1 patients displayed the loss of MLH1/PMS2, PMS2, MSH6, and MSH2/MSH6, respectively. All nine patients were male with a median age of 68 years (63–79 years). One had been previously diagnosed as having LS with an MSH2 variant. Genetic testing demonstrated the presence of a pathogenic PMS2 variant (n = 1), a variant of uncertain significance in MSH2 (n = 1), and no pathogenic germline variants of the MMR genes (n = 1). One patient with MSH6-deficient BC did not complete the genetic testing because of severe degradation of DNA extracted from the FFPE specimen, but the patient was strongly suspected to have LS because of their history of colon cancer and MSH6-deficient upper urinary tract cancer. There remained a possibility that the remaining four patients who refused genetic testing had LS. The prevalence of LS-associated MMR-deficient BC was estimated to be 0.6–1.1% among unselected BC cases.

The current World Health Organization (WHO) classification defines a new disease entity of high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements, making fluorescence in situ hybridization (FISH) screening for these genes mandatory. In addition, the prognostic significance of MYC expression was reported, with a cut-off value of 40%. However, interobserver discrepancies arise due to the heterogeneous intensity of MYC expression by immunohistochemistry. Moreover, a cut-off value of positivity for MYC protein in diffuse large B-cell lymphoma (DLBCL) varies among studies at present. Here, we applied a high-sensitivity semiquantitative immunohistochemical technique using fluorescent nanoparticles called phosphor-integrated dots (PID) to evaluate the MYC expression in 50 de novo DLBCL cases, and compared it with the conventional diaminobenzidine (DAB)-developing system. The high MYC expression detected by the PID-mediated system predicted poor overall survival in DLBCL patients. However, we found no prognostic value of MYC protein expression for any cut-off value by the DAB-developing system, even if the intensity was considered. These results indicate that the precise evaluation of MYC protein expression can clarify the prognostic values in DLBCL, irrespective of MYC rearrangement.

Background The goal was to determine whether the addition of temozolomide (TMZ) to the standard treatment of high-dose methotrexate (HD-MTX) and whole-brain radiotherapy (WBRT) for primary central nervous system lymphoma (PCNSL) improves survival. Methods An open-label, randomized, phase III trial was conducted in Japan, enrolling immunocompetent patients aged 20–70 years with histologically confirmed, newly diagnosed PCNSL. After administration of HD-MTX, patients were randomly assigned to receive WBRT (30 Gy) ± 10 Gy boost (arm A) or WBRT ± boost with concomitant and maintenance TMZ for 2 years (arm B). The primary endpoint was overall survival (OS). Results Between September 29, 2014 and October 15, 2018, 134 patients were enrolled, of whom 122 were randomly assigned and analyzed. At the planned interim analysis, 2-year OS was 86.8% (95% confidence interval [CI]: 72.5–94.0%) in arm A and 71.4% (56.0–82.2%) in arm B. The hazard ratio was 2.18 (95% CI: 0.95–4.98), with the predicted probability of showing the superiority of arm B at the final analysis estimated to be 1.3%. The study was terminated early due to futility. O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status was measured in 115 tumors, and it was neither prognostic nor predictive of TMZ response. Conclusions This study failed to demonstrate the benefit of concomitant and maintenance TMZ in newly diagnosed PCNSL.

Background The prevalence and molecular characteristics of deficient mismatch repair prostate cancer in the Japanese population have scarcely been investigated. Methods Immunohistochemistry for mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) was performed in formalin-fixed paraffin-embedded sections prepared from resected primary prostate cancers in patients who underwent prostatectomy at our institution between January 2001 and May 2016. Genetic and/or epigenetic alterations of mismatch repair genes were investigated in patients with any loss of mismatch repair protein expression in the tumour. Results Of the 337 patients, four (1.2%) showed loss of mismatch repair protein expression on immunohistochemistry. All four patients showed loss of both MSH2 and MSH6 protein expression. Genetic testing was performed in two of the four patients, demonstrating no pathogenic germline alterations were present. In each of these two patients, at least one somatic alteration inactivating MSH2 without MSH2 hypermethylation was identified, leading to the diagnosis of supposed ‘Lynch-like syndrome’. Patients with deficient mismatch repair prostate cancer were at a significantly higher stage (pT2pN0 vs. pT3-4pN0/pTanypN1, P = 0.02) and had a greater Gleason score ( Conclusions The prevalence of deficient mismatch repair prostate cancer in the Japanese hospital-based prostatectomized population was extremely low. To improve screening efficacy for deficient mismatch repair prostate cancer, screening candidates can be limited to patients with locally advanced, node-positive and/or Gleason score of 8 or greater prostate cancer. Universal tumour screening for Lynch syndrome seems ineffective in patients with prostate cancer.

Duodenal cancer is a leading cause of death after colectomy in patients with familial adenomatous polyposis (FAP). Detailed endoscopic evaluation of duodenal lesions with potential for carcinoma development is therefore mandatory. Here we investigated the features of duodenal lesions in FAP patients using an endocytoscopy system (ECS). We retrospectively reviewed duodenal lesions in 15 cases of FAP using an ECS (GIF-H290EC) with methylene blue (MB) as the vital dye. With reference to the Spigelman classification, we investigated the number of lesions using white light (WL), narrow-band imaging (NBI), and MB staining. Using the maximum magnification power of the ECS we investigated the histology (duct openings or finger-like projections) and grade of dysplasia (presence or absence of enlarged oval-shaped nuclei) of the lesions. The number of duodenal lesions increased in ascending order of WL, NBI, and MB (P

MYC-associated factor X (MAX) is a protein in the basic helix-loop-helix leucine zipper family, which is ubiquitously and constitutively expressed in various normal tissues and tumors. MAX protein mediates various cellular functions such as proliferation, differentiation, and apoptosis through the MYC-MAX protein complex. Recently, it has been reported that MYC regulates the proliferation of anaplastic large cell lymphoma. However, the expression and function of MAX in anaplastic large cell lymphoma remain to be elucidated. We herein investigated MAX expression in anaplastic large cell lymphoma (ALCL) and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) and found 11 of 37 patients (30%) with ALCL lacked MAX expression, whereas 15 of 15 patients (100%) with PTCL-NOS expressed MAX protein. ALCL patients lacking MAX expression had a significantly inferior prognosis compared with patients having MAX expression. Moreover, patients without MAX expression significantly had histological non-common variants, which were mainly detected in aggressive ALCL cases. Immunohistochemical analysis showed that MAX expression was related to the expression of MYC and cytotoxic molecules. These findings demonstrate that lack of MAX expression is a potential poor prognostic biomarker in ALCL and a candidate marker for differential diagnosis of ALCL and PTCL-NOS.

Regressive lymphoproliferative disorders (R-LPD) after methotrexate (MTX) withdrawal are one of the specific features of methotrexate - associated lymphoproliferative disorders (MTX-LPD). Although the impact of the absolute lymphocyte count (ALC) on the pathogenesis of R-LPD has been recently emphasized, understanding relapse/regrowth events (RRE) and differences among LPD subtypes is necessary. In this study, we confirmed ALC recovery in the regressive group (R-G; R-LPD without RRE) and relapse/regrowth group (R/R-G; R-LPD with RRE). The increase in ALC lasted at least 2 years in R-G, whereas it decreased within 3 years in R/R-G, supporting the better overall survival (OS) in R-G, as previously reported. In addition, our study suggested that an ALC of 1000/µL at the time of development of LPD is a significant predictor for treatment-free survival (TFS). Furthermore, an ALC of 1000/µL at 6 months after MTX withdrawal was found to be a significant indicator of TFS and OS for R-G and R/R-G. The ALC decreased gradually before LPD development in R/R-G, whereas it decreased 6 months before LPD development in R-G, confirming the important role of ALC in the pathogenesis of MTX-LPD such as regressive events and RRE. In addition to ALC, other predictive factors, such as serum C-reactive protein and soluble interleukin-2 receptors, may be helpful in the management of MTX-LPD, including the decision making for an additional chemotherapy for regressive LPD after MTX withdrawal.

Background Chronic spinal epidural hematomas (SEHs) are rare clinical entities. SEH with vertebral scalloping is extremely rare, with only a few cases having been reported to date. We report a unique case of spontaneous chronic SEH in the lumbar spine with severe vertebral scalloping mimicking an epidural tumor. Case presentation A 71-year-old man presented with a 2-month history of lumbar pain and a 3-week history of paresthesia and pain in the right lower extremity, hypesthesia in the perineal and perianal regions, and bladder dysfunction. Computed tomography following myelography revealed an epidural mass lesion on the right side that compressed the dural sac and was associated with severe bony scalloping on the posterior wall of the L4 vertebral body. Magnetic resonance imaging (MRI) on T1- and T2-weighted images revealed a space-occupying lesion with heterogeneous intensity, and T1-gadolinium images showed an intralesional heterogeneous enhancement effect. A tumoral lesion in the spinal canal was suspected, based on preoperative imaging; therefore, a total spinal tumor resection was planned. Intraoperative findings revealed that the brownish lesion adhered to the dura and epidural tissues in the spinal canal, and the space-occupying mass in the scalloped cavity of the posterior wall of the L4 vertebra was encapsulated in red-brownish soft tissues. The lesion was totally resected in a piecemeal fashion, and pathological examination revealed a mixture of tissues that contained a relatively new hematoma with hemoglobin, as well as an obsolete hematoma with hemosiderin and amyloid deposits. The mass was diagnosed as a chronic epidural hematoma with recurrent hemorrhage. The postoperative course was uneventful, and the preoperative neurological symptoms immediately improved. Conclusions The preoperative diagnosis of chronic SEHs is challenging, as MRI results may not be conclusive, particularly in patients with scalloping of bony structures. Thus, chronic SEHs should be considered as a differential diagnosis in cases of suspected tumoral lesions in the spinal canal. To the best of our knowledge, this is the first reported case of acute exacerbation of chronic SEH with cauda equina syndrome and severe vertebral scalloping.

Intravascular large B-cell lymphoma (IVLBCL) is a rare lymphoma characterized by the selective growth of lymphoma cells within the lumen of vessels. We describe the case of a 69-year-old male who presented with marked pain in the left facial region. Gadolinium-enhanced magnetic resonance imaging revealed a swollen left trigeminal nerve (TN) and positron emission tomography/computed tomography demonstrated fluorodeoxyglucose-only uptake at the same site. The patient had high serum lactate dehydrogenase and soluble interleukin-2 receptor levels. As random skin biopsy and bone marrow biopsy detected no abnormal pathogenesis, open biopsy of the TN was performed, revealing diffuse large B-cell lymphoma (DLBCL). However, ground glass opacities rapidly developed in both lung fields with severe respiratory failure. The patient died of progressive disease before the initiation of chemotherapy. Postmortem examination revealed widespread lymphoma cells in the lumen of vessels in multiple organs, including the lungs, excluding the bone marrow and skin. Lymphoma cells formed a mass in the TN and left lumbar plexus. A diagnosis of IVLBCL was made based on the postmortem pathological analysis. DLBCL of abnormal sites, such as the peripheral nervous system, should be considered in cases of IVLBCL as a differential diagnosis.

The tumor microenvironment (TME) is a critical regulator of the development of malignant lymphoma. Therapeutics targeting the TME, especially immune checkpoint molecules, are changing the treatment strategy for lymphoma. However, the overall response to these therapeutics for diffuse large B-cell lymphoma (DLBCL) is modest and new targets of immunotherapy are needed. To find critical immune checkpoint molecules for DLBCL, we explored the prognostic impact of immune checkpoint molecules and their ligands using publicly available datasets of gene expression profiles. In silico analysis of three independent datasets (GSE117556, GSE10846, and GSE181063) revealed that DLBCL expressing CD24 had a poor prognosis and had a high frequency of MYC aberrations. Moreover, gene set enrichment analysis showed that the 'MYC-targets-hallmark' (false discovery rate [FDR] = 0.024) and 'inflammatory-response-hallmark' (FDR = 0.001) were enriched in CD24-high and CD24-low DLBCL, respectively. In addition, the expression of cell-specific markers of various immune cells was higher in CD24-low DLBCL than in CD24-high DLBCL. CIBERSORT analysis of the datasets showed fewer macrophages in CD24-high DLBCL than in CD24-low DLBCL. Additionally, immunohistochemical analysis of 335 cases of DLBCL showed that few TME cells were found in CD24-high DLBCL, although statistical differences were not observed. These data indicate that CD24 expression suppresses immune cell components of the TME in DLBCL, suggesting that CD24 may be a target for cancer immunotherapy in aggressive large B-cell lymphoma.

Primitive myxoid mesenchymal tumor of infancy (PMMTI) is a rare soft tissue sarcoma in childhood. We present the case of a newborn male who experienced a severe hemorrhage in utero from the tumor on the scalp. He died at the age of 24 hours owing to hemorrhagic shock. The tumor was posthumously diagnosed as PMMTI. A literature search indicated that cases of severe hemorrhage from soft tissue sarcomas in utero or at birth are limited to infantile fibrosarcoma. This is the first case of PMMTI with massive hemorrhage. Clinicians must be aware of hemorrhagic complications of PMMTI.

Background Desmoplastic fibroblastoma (also known as collagenous fibroma) is a benign, slowly growing soft-tissue tumor. Most desmoplastic fibroblastomas develop in the limbs, neck, or trunk. A mediastinal origin is quite rare. Case presentation A 32-year-old Asian female was referred to us for the diagnosis and treatment of an anterior mediastinal tumor. The tumor was 80 mm in the largest diameter and was located on the pericardium. No invasion was evident. She underwent resection of the tumor via video-assisted thoracoscopic resection. The tumor was totally encapsulated, and its pedicle was on the pericardium. The resected specimen was very rigid, making it difficult to remove from the intercostal space. Histologically, the tumor was composed of a paucicellular dense collagenous tissue. Mitosis was rarely observed, and cellular atypia was not evident, suggesting that the tumor was benign. We diagnosed the tumor as a desmoplastic fibroblastoma by morphology and immunohistochemistry. Conclusions Desmoplastic fibroblastoma of the mediastinum is an extremely rare disease. Preoperative diagnosis is difficult. Early surgical resection is suitable for diagnosis and treatment planning.

We compared the two methods of assessing CD30 protein expression in DLBCL and TCL specimens routinely employed at our hospital, immunohistochemistry (IHC) and flow cytometry (FCM), using the same clone of the anti-CD30 antibody (Ber-H2) in 123 patients with DLBCL and 28 patients with TCL. FCM was more sensitive than IHC, especially in cases with low expression. In three cases of TCL and two cases of DLBCL, there was discordance between these two methods. Two of these TCL cases were ALCL and one was peripheral T-cell lymphoma, NOS, but ALCL was unable to be excluded. One of two cases of DLBCL was an anaplastic variant of DLBCL. The data suggested that CD30 was undetectable, though rare, by FMC in several cases. Based on this study, a combination of IHC and FCM is recommended for the reliable and quantitative detection of CD30.

BackgroundThe prevalence of Lynch syndrome and the use of universal tumor screening to identify Lynch syndrome among unselected patients with upper urinary tract urothelial carcinoma, which is associated with Lynch syndrome, have not been closely investigated yet.MethodsA total of 166 tumors from 164 upper urinary tract urothelial carcinoma patients were tested for microsatellite instability and expression of mismatch repair proteins (MLH1, MHS2, MSH6 and PMS2) by immunohistochemistry. Genetic testing was performed for patients suspected of having Lynch syndrome. Clinicopathological factors, including familial and personal cancer history associated with mismatch repair deficiency, were evaluated.ResultsThe frequency of high-level microsatellite instability and loss of at least one mismatch repair protein was 2.4% (4/164); the microsatellite instability and immunohistochemistry results showed complete concordance. Of these four patients, three were genetically proven to have Lynch syndrome, while the remaining one was highly suggestive for Lynch syndrome based on their personal cancer history. Univariate analysis showed that ageConclusionsThe prevalence of Lynch syndrome among unselected upper urinary tract urothelial carcinoma patients was at least 1.8% in our study population. The screening efficacies of the microsatellite instability test and immunohistochemistry appear equivalent. Universal tumor screening may be a valid approach; however, selective screening methods that consider factors associated with mismatch repair loss/high-level microsatellite instability tumors require further investigation.

Background A hydatidiform mole with a coexisting fetus is a rare condition that commonly occurs as either a partial mole with fetus or a twin pregnancy comprising a complete mole and normal fetus. In the former case, the fetus is triploid, and in the latter case, the fetus is diploid with different alleles from those of the mole. Because there is a difference in the persistent trophoblastic disease incidence between the two, an accurate diagnosis is required. Case presentation We present a case of a 34-year-old Japanese woman who was pregnant with a hydatidiform mole and two coexisting fetuses. At 17 weeks of gestation, hemorrhage-induced progressive anemia in the mother prompted the decision to terminate the pregnancy, after which no complications occurred. Molecular cytogenetic analysis revealed that one of the fetuses was a normal diploid fetus with the same allele in the fetus and placenta. The hydatidiform mole was revealed to be a mosaic of two diploids, and the other coexisting fetus was a normal diploid that shared one of the mole alleles. Conclusions This was presumed to be a rare case of twin pregnancy by triploid embryo formation, followed by loss of an allele due to postzygotic diploidization, development of a diploid fetus, and development of another fetus from a separate embryo. Because of the existence of cases such as this one with a diploid fetus, but without a normal pregnancy coexistent with a complete hydatidiform mole, diagnosis by genetic analysis is required for prognosis.

Methotrexate (MTX) is one of the potent drugs for autoimmune diseases (ADs), especially for rheumatoid arthritis. Recent studies suggest that MTX should be immediately withdrawn when patients with AD develop lymphoproliferative disorder (LPD). However, biopsy cannot be performed for diagnosis because LPD regresses quickly after MTX withdrawal, thus making clinical MTX-LPD (c-MTX-LPD) challenging to diagnose. In this study, among the 28 patients with c-MTX-LPD, seven developed a proven LPD (p-LPD) after suspicious LPD (s-LPD) regression, six of which were Hodgkin lymphoma. Four of seven patients with p-LPD + died, whereas all patients with p-LPD- survived. The clinical manifestations indicative of p-LPD include fever, elevated serum C-reactive protein level, and soluble interleukin-2 receptor level. Anti-AD drugs did not appear to affect the pathogenesis of p-LPD development. P-LPD was not observed after 3 years from the time of s-LPD regression.

Although intravascular large B-cell lymphoma (IVLBCL) is an extranodal lymphoma characterized by the selective growth of lymphoma cells within the lumina of small vessels, we here report three autopsy cases of IVLBCL characterized by the proliferation within large blood vessels. These three cases were diagnosed as IVLBCL of the bone marrow or skin biopsy. Two cases died suddenly before treatment, whereas the other died during treatment. Autopsies showed a large embolus of dense lymphoma cells extending from the truncus pulmonalis to the pulmonary arteries in Case 1, emboli of lymphoma cells in the aorta and carotis in Case 2, and a mass of lymphoma cells blocking the lumen of the aortic arch in Case 3. This is the first report of IVLBCL involving large blood vessels, and it is essential to note that this type of IVLBCL might cause sudden death because of tumor emboli within large blood vessels.

Other iatrogenic immunodeficiency-associated lymphoproliferative disorders (OIIA-LPD), a category of immunodeficiency-associated LPD according to the World Health Organization classification, is associated with immunosuppressive drugs (ISDs). Several factors, including autoimmune disease (AID) activity, Epstein-Barr virus (EBV) infection, ISD usage, and aging, influence the development of OIIA-LPD, resulting in complicated clinical courses and outcomes. Most OIIA-LPD develops in patients with rheumatoid arthritis using methotrexate (MTX-LPD). The management of MTX-LPD is based on the clinical course, i.e., with/without regression, with/without relapse/regrowth event (RRE), LPD subtype, and ISDs for AIDs after LPD development. There are three clinical courses after ISD withdrawal: regressive LPD without relapse/regrowth (R-G), regressive LPD with RRE (R/R-G), and persistent LPD (P-G). The majority of EBV+ diffuse large B-cell lymphomas are classified in R-G, whereas classic Hodgkin lymphoma is generally classified in R/R-G. Polymorphic LPD (P-LPD) in MTX-LPD develops with heterogeneous pathological features similar to monomorphic LPD. Chemotherapy for MTX-LPD is selected according to that for de novo LPD, although the strategy for aggressive P-LPD and non-specific LPD is not well established. The absolute lymphocyte count in the peripheral blood has been suggested as a candidate marker for MTX-LPD development and RRE. Several clinical issues, including correct diagnosis among overlapping clinicopathological features in MTX-LPD and clinical management of LPD by ISDs other than MTX, require further investigation.

In the current revised 4th edition of the World Health Organization (WHO) classification, ‘other iatrogenic immunodeficiency-associated lymphoproliferative disorders (Oii-LPDs)’ is listed in the last section in the chapter on immunodeficiency-associated lymphoproliferative disorders. Oii-LPDs cover a broad spectrum from benign lesions to lymphoma, and correspond to one of the subtypes in the WHO classification for immunocompetent patients. The WHO classification does not clearly indicate the histological subtype of this disease category; however, the framework of subtype classification is similar to the classification of post-transplant lymphoproliferative disorders, and recent studies have attempted to subcategorize Oii-LPDs that fit this unique disease type. In this review, we provide an overview of B-cell-type Oii-LPDs regarding their histopathology and immunophenotype, genetics and clinical behaviors.

The endocytoscopic system (ECS) helps in virtual realization of histology and can aid in confirming histological diagnosis in vivo. We propose replacing biopsy-based histology for esophageal squamous cell carcinoma (ESCC) by using the ECS. We applied deep-learning artificial intelligence (AI) to analyse ECS images of the esophagus to determine whether AI can support endoscopists for the replacement of biopsy-based histology. A convolutional neural network-based AI was constructed based on GoogLeNet and trained using 4715 ECS images of the esophagus (1141 malignant and 3574 non-malignant images). To evaluate the diagnostic accuracy of the AI, an independent test set of 1520 ECS images, collected from 55 consecutive patients (27 ESCCs and 28 benign esophageal lesions) were examined. On the basis of the receiver-operating characteristic curve analysis, the areas under the curve of the total images, higher magnification pictures, and lower magnification pictures were 0.85, 0.90, and 0.72, respectively. The AI correctly diagnosed 25 of the 27 ESCC cases, with an overall sensitivity of 92.6%. Twenty-five of the 28 non-cancerous lesions were diagnosed as non-malignant, with a specificity of 89.3% and an overall accuracy of 90.9%. Two cases of malignant lesions, misdiagnosed as non-malignant by the AI, were correctly diagnosed as malignant by the endoscopist. Among the 3 cases of non-cancerous lesions diagnosed as malignant by the AI, 2 were of radiation-related esophagitis and one was of gastroesophageal reflux disease. AI is expected to support endoscopists in diagnosing ESCC based on ECS images without biopsy-based histological reference.

We describe the case of an elderly Japanese female who had experienced diabetic nephropathy since the year 20xx and had been undergoing dialysis treatment while receiving vascular access interventional therapy (VAIVT) for arteriovenous fistula (AVF) occlusion. The patient visited the clinic/hospital in 20xx+10 with the AVF occlusion; emergency VAIVT was performed but blood flow could not be resumed. The patient was not admitted and was treated as an outpatient, and thus a cuff catheter (Split stream catheter: SST28 cm, Medcomp) was inserted. An infection developed and was successfully treated with antibiotics. The dialysis treatment continued without issue. One year after the cuff catheter’s insertion, the patient was admitted due difficulty breathing. Despite continued dialysis treatment with the catheter, the patient died 15 days post-admission. The removal of the catheter proved to be difficult. An autopsy was approved, and the area around the catheter was examined. The adhesion of the catheter to the right atrium was observed, but no infection was detected in the bloodstream. This case illustrates that dialysis with the use of a cuff catheter can be effective.

Background:Desmoplastic fibroblastoma (also known as collagenous fibroma) is a benign, slowly growing soft tissue tumor. Most desmoplastic fibroblastomas develop in the limbs, neck, or trunk. A mediastinal origin is quite rare.Case presentation:A 32-year-old female was referred to us for the diagnosis and treatment of an anterior mediastinal tumor. The tumor was 80 mm in the largest diameter and was located on the pericardium. No invasion was evident. She underwent resection of the tumor via video-assisted thoracoscopic resection. The tumor was totally encapsulated, and its pedicle was on the pericardium. The resected specimen was very rigid, making it difficult to remove from the intercostal space. Histologically, the tumor was composed of a paucicellular dense collagenous tissue. Mitosis was rarely observed, and cellular atypia was not evident, suggesting that the tumor was benign. We diagnosed the tumor as a desmoplastic fibroblastoma by morphology and immunohistochemistry.Conclusions:Desmoplastic fibroblastoma of the mediastinum is a rare disease. Preoperative diagnosis is difficult. Early surgical resection is suitable for diagnosis and treatment planning.

Background The attention on mismatch repair-deficient (dMMR) gastric cancer has increased in this era of anti-PD-1 blockade therapy; however, the prevalence and molecular genetics of patients with dMMR gastric cancer have not been completely investigated. Methods Immunohistochemistry of MMR proteins (MLH1, MSH2, MSH6 and PMS2) was performed on formalin-fixed paraffin-embedded sections prepared from resected primary gastric cancers of 513 consecutive patients. Genetic and/or epigenetic alterations of the MMR genes were also investigated. Results Loss of expression of one or more MMR proteins was observed in 58 patients (11.3%); 54 patients showed loss of MLH1/PMS2, 3 patients showed loss of MLH1/PMS2/MSH6 and 1 patient showed loss of PMS2 alone. Among these 58 patients, 55 showed hypermethylation of the promoter region of MLH1. Genetic testing revealed that the remaining three patients had Lynch syndrome (n = 1) or Lynch-like syndrome (n = 2). A total of 15 patients (25.9% of all patients with dMMR gastric cancer and 2.9% of all patients with gastric cancer), including 11 patients with stage I–III dMMR gastric cancer who had recurrence and 4 patients with stage IV dMMR gastric cancer, are potential candidates for the use of anti-PD-1 blockades. Conclusions This is the first study to investigate the frequency and molecular genetic mechanisms of dMMR gastric cancer comprehensively, focusing on the benefit of using PD-1 blockades. Our observations will be beneficial in the clinical practice of metastatic gastric cancer.

BackgroundThe prevalence and molecular characteristics of defective DNA mismatch repair endometrial cancers in the Japanese population have been underexplored. Data supporting clinical management of patients with Lynch-like syndrome and germline variant of uncertain significance of mismatch repair genes are still lacking.MethodsImmunohistochemistry of mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) was performed on formalin-fixed paraffin-embedded sections prepared from resected primary endometrial cancers in 395 women with a median age of 59 years. Genetic and/or epigenetic alterations of the mismatch repair genes were also investigated.ResultsLoss of expression of one or more mismatch repair proteins was observed in 68 patients (17.2%). A total of 17 out of 68 patients (25%, 4.3% of all cases) were identified as candidates for genetic testing for Lynch syndrome after excluding 51 patients with MLH1 hypermethylated cancer. Fourteen of these 17 patients subjected to genetic testing were found to have Lynch syndrome (n = 5), germline variant of uncertain significance (n = 2) or Lynch-like syndrome (n = 7). Compared with patients with Lynch syndrome, those with germline variant of uncertain significance and Lynch-like syndrome tended to demonstrate an older age at the time of endometrial cancer diagnosis (P = 0.07), less fulfillment of the revised Bethesda guidelines (P = 0.09) and lower prevalence of Lynch syndrome-associated tumors in their first-degree relatives (P = 0.01).ConclusionsThis study provides useful information for management in patients with DNA mismatch repair endometrial cancer. Specifically, cancer surveillance as recommended in patients with Lynch syndrome might not be necessary in patients with germline variant of uncertain significance and Lynch-like syndrome and their relatives.

Background Muir-Torre syndrome (MTS) is currently considered as a clinical variant of Lynch syndrome (LS). The clinical significance of the screening of patients with MTS-associated cutaneous tumors for the identification of LS has not yet been established. In addition, the prevalence and molecular characteristics of mismatch repair (MMR) protein deficiency in such tumors has scarcely been investigated in the Japanese population. Methods Immunohistochemistry (IHC) for MMR proteins (MLH1, MSH2, MSH6 and PMS2) was performed in formalin-fixed paraffin-embedded sections prepared from 16 sebaceous neoplasms (SNs) resected from 13 patients and 32 keratoacanthomas (KAs) resected from 31 patients at our institution between January 2005 and March 2014. Tumors showing MMR protein loss were further subjected to genetic analysis for detecting the presence of germline and/or somatic alterations of the MMR genes to identify the precise molecular mechanisms underlying the protein loss. Results Among the 16 SNs resected from 13 patients, eight SNs resected from five patients (38.5%) showed loss of expression of MMR proteins (MLH1/PMS2 loss, one patient; MSH2/MSH6 loss, four patients). Genetic analyses showed a pathogenic germline MSH2 mutation in one patient, somatic hypermethylation of the MLH1 promoter region in one patient, and somatic alterations of MSH2 without detectable germline mutations of MSH2 in three patients. None of the KAs examined in the study showed any loss of MMR protein expression. Conclusions The efficacy of routine screening of cutaneous neoplasms known to be associated with MTS by IHC for MMR proteins to identify LS may be fairly limited. MMR protein loss as determined by IHC in SNs is not always diagnostic of LS, and appears, in most cases, to be a result of somatic inactivation of the MMR genes.

Introduction The prognosis of classic Hodgkin lymphoma (cHL) in young adults has improved following advances in current therapeutics. However, evidence of elderly patients with cHL has limited due to its rarer. To analyze clinical outcomes and risk factors in elderly patients with advanced-stage cHL who received a doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) regimen, we conducted a nationwide multi-center retrospective study in Japan (UMIN000033264). Methods The key eligibility criteria of the current study were as follows: 1) patients with histologically diagnosed cHL between 2007 and 2016 in each institution; 2) advanced-stage cHL (stage III, IV or IIB with bulky or extranodal lesion); 3) age at diagnosis > 60 years; and 4) had received at least one cycle of an ABVD regimen as initial treatment including a modified ABVD regimen (dacarbazine dose reduced to 250 mg/m 2 at first cycle). Patients with human immunodeficiency virus infection or methotrexate-associated cHL were excluded. The primary endpoint was 5-year overall survival (OS). Secondary endpoints included progression-free survival (PFS) and event-free survival (EFS), the latter defined as the time from a diagnosis of cHL to disease progression or relapse, subsequent systemic chemotherapy for cHL, or death due to any cause in this study. The average relative dose intensity (ARDI) of ABVD was calculated as the sum of the relative dose intensity of each drug divided by four. Results A total of 171 patients from 45 institutions were included in this study. The central pathological review could be performed in 140 cases (82%), in which histological subtypes of cHL were determined as follows: mixed cellularity, 89 (64%); nodular sclerosis, 33 (24%); lymphocyte-deleted, 4 (3%); lymphocyte-rich, 2 (1%); not otherwise specified, 12 (9%). The median age was 71 years (interquartile range [IQR] 65-76). The number of patients in each 10-year age group was 79 (46%) for 61-70 years, 78 (46%) for 71-80 years, and 14 (8%) for > 81 years. The numbers of patients with ECOG performance status (PS) ≥2 and B symptoms were 33 (19%) and 85 (50%), respectively. Bulky mediastinal diseases were found in four patients (2%). The risk factors used for the International Prognostic Score (IPS), including male sex, stage IV, hypoalbuminemia, anemia, leukocytosis, and lymphopenia, were not significantly different among these age groups. The median number of cycles of ABVD was 6 (IQR:5-7), and 66% of patients completed at least 6 cycles. The median ARDI was 77%. The median ARDI in each 10-year age group was 88% for 61-70 years, 71% for 71-80 years, and 54% for > 81 years. With a median follow-up time of 52 months (IQR:31-76), the estimated OS, PFS, and EFS at 5 years were 72%, 59%, and 54%, respectively. Among 131 patients whose Epstein-Barr virus (EBV) status was analyzed using EBV-encoded small RNA1 (EBER1) in situ hybridization, 61 (46%) were positive for EBER1. The OS was not significantly different between EBV-positive and EBV-negative patients (75% and 76% at 5 years, respectively). Univariate analysis for OS revealed that age, PS ≥ 2, hypoalbuminemia, anemia, lymphopenia, and the presence of B symptoms were significantly associated with short OS. In multivariate analysis, age (hazard ratio [HR] 1.568 per 10-year increase, 95% confidence interval [CI] 1.020-2.411) was only an independent risk factor for OS, whereas lymphopenia (HR 1.967, 95% CI 1.196-3.235) was an independent risk factor for EFS. Higher ARDI was significantly associated with improved OS and EFS. Bleomycin-induced lung toxicity (BLT), observed in 41 (24%) patients, was not associated with OS. In this study, we found that 55 patients died: 23 within two years after diagnosis mainly due to cHL progression (n = 10, 43%) and treatment-related toxicity (infection [n = 4, 17%] and BLT [n = 4, 17%]). The remaining 32 patients died more than two years after diagnosis mainly due to second primary malignancies (n = 14, 44%), including solid tumors (n = 6), other types of lymphoma (n = 4), and myelodysplastic syndrome/acute myeloid leukemias (n = 4). Conclusions The HORIZON study showed relatively good prognosis for elderly patients with advanced-stage cHL who received an ABVD regimen (estimated five-year OS rates was 72%). Age and lymphopenia were an independent risk factors for OS and EFS, respectively. The development of novel therapies is warranted to improve the outcomes of such patients. Disclosures Makita: SymBio: Honoraria; Novartis: Honoraria; Eisai: Honoraria; Daiichi-Sankyo: Consultancy; CSL Behring: Honoraria; Chugai: Honoraria; BMS: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Kusumoto: Kyowa Kirin: Honoraria; Chugai: Honoraria, Research Funding; Daiichi Sankyo: Research Funding. Tsujimura: Takeda: Honoraria; Chugai: Honoraria; Kyowa Kirin: Honoraria; Eisai: Honoraria; Janssen: Honoraria. Takayama: Chugai: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding. Kuroda: Otsuka Pharmaceutical: Honoraria, Research Funding; Astellas Pharma: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; MSD: Research Funding; Abbvie: Consultancy, Honoraria; Ono Pharmaceutical: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Sysmex: Research Funding; Pfizer: Honoraria, Research Funding; Nippon Shinyaku: Honoraria, Research Funding; Shionogi: Research Funding; Asahi Kasei: Research Funding; Taiho Pharmaceutical: Research Funding; Fujimoto Pharmaceutical: Current Employment, Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Dainippon Sumitomo Pharma: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Bristol-MyersSquibb: Consultancy, Honoraria, Research Funding; Janssen Pharmaceutical K.K: Consultancy. Shimada: BMS: Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Takeda: Honoraria; Janssen: Honoraria; Chugai: Consultancy, Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Daiichi Sankyo: Consultancy, Honoraria, Research Funding; AstraZeneca: Honoraria; Otsuka: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; SymBio: Honoraria. Okamoto: Chugai: Research Funding; Kyowa Kirin: Research Funding; Ono: Research Funding; Taiho: Research Funding; Takeda: Research Funding. Asano: Takeda: Honoraria. Maruyama: Janssen: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Novartis: Research Funding; MSD: Honoraria, Research Funding; Otsuka: Research Funding; Ono: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Astellas Pharma,: Research Funding; Celgene: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; Amgen: Research Funding; BMS: Honoraria, Research Funding; Mundipharma: Honoraria; Kyowa Kirin: Honoraria; Zenyaku: Honoraria; AstraZeneca: Honoraria; Nippon: Honoraria; SymBio: Honoraria. Yamaguchi: Chugai: Honoraria, Research Funding; Genmab: Research Funding; MSD: Honoraria; Kyowa Kirin: Honoraria, Research Funding; Takeda: Honoraria; Ono: Honoraria; Celgene: Honoraria; Otsuka: Honoraria; Sumitomo Dainippon: Honoraria; Eisai: Honoraria; AstraZeneca: Consultancy. Nagai: AbbVie: Research Funding; AstraZeneca: Honoraria, Research Funding; Bayer: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Chordia Therapeutics: Honoraria; Chugai Pharmaceutical: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Kyowa Kirin: Research Funding; Mundipharma: Honoraria, Research Funding; Nippon Shinyaku: Research Funding; Novartis: Honoraria; Ono Pharmaceutical: Honoraria; Sanofi: Honoraria; Sumitomo Dainippon Pharma: Honoraria; SymBio Pharmaceuticals: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; Zenyaku Kogyo: Research Funding.

The relationship between thymidine phosphorylase (TP) and angiogenesis at the early stage of esophageal squamous cell carcinoma has been unclear. Using 14 samples of normal squamous epithelium, 11 samples of low-grade intraepithelial neoplasia, and 64 samples of superficial esophageal cancer, microvessel density (MVD) was estimated using immunostaining for CD34 and CD105. TP expression was also evaluated in both cancer cells and stromal monocytic cells (SMCs). We then investigated the correlation between MVD and TP expression in both cancer cells and SMCs. On the basis of the above parameters, MVD was significantly higher in cancerous lesions than in normal squamous epithelium. In terms of CD34 and CD105 expression, MVD showed a gradual increase from normal squamous epithelium, to low-grade intraepithelial neoplasia, and then to M1 and M2 cancer, and M3 or deeper cancer. M1 and M2 cancer showed overexpression of TP in both cancer cells and SMCs. There was no significant correlation between TP expression in cancer cells and MVD estimated from CD34 (rS = 0.16, P = 0.21) or CD105 (rS = 0.05, P = 0.68) expression. Significant correlations were found between TP expression in SMCs and CD34-related (rS = 0.46, P

To clarify the prevalence and clinicopathologic/molecular characteristics of mismatch repair (MMR)-deficient colorectal cancer in the young Japanese population. Immunohistochemical analyses for MMR proteins (MLH1, MSH2, MSH6, and PMS2) were performed in formalin-fixed paraffin-embedded sections prepared from the resected CRC specimens of 119 consecutive patients aged

Recently, attention has been focused on methotrexate-induced lymphoproliferative disease (MTX-LPD), and atypical phenotypes are occasionally documented. We encountered two patients with rheumatoid arthritis (RA) who were diagnosed with non-specific LPD (LPD-nos). Biopsy samples were not obtained during the initial examination when the LPD development was discovered, and the patients achieved a complete response after MTX cessation (case 1) or steroid pulse therapy (case 2). However, the tumors flared up 1.5 years later, and LPD-nos was determined following biopsies of the lymph node (LN, case 1) and liver (case 2). Prednisolone was subsequently administered instead of chemotherapy; however, multiple masses, including in the spine (case 1), and severe icterus with liver dysfunction (case 2) were exacerbated within a few months. Although the re-biopsy of LN proved the presence of HL and radiation followed by aggressive chemotherapy rescued the patient (case 1), the superficially accessible biopsy site was not found, and autopsy finally revealed HL (case 2). In both cases, the underlying pathogenesis along with the B symptoms and laboratory abnormalities suggested MTX-LPD, HL in particular. Therefore, even if the pathological diagnosis does not confirm the specific LPD subtype, the administration of aggressive chemotherapy should be considered if the LPD activity flares severely.

A 47-year-old woman was transferred to our hospital in June 2014 in hemorrhagic shock due to rupture of a huge right renal angiomyolipoma (AML). Selective right renal arterial embolization performed that same day reversed the shock immediately. Despite the huge abdominal tumor, the patient was discharged 2 weeks later after refusing any further treatment.Two weeks later she noticed the abdominal tumor growing. One month after discharge, she was readmitted due to dyspnea caused by restriction of her breathing by the growing tumor mass. A CT revealed a massive increase in tumor size with internal liquefaction, a thrombus in the left common iliac vein, and a 12 mm aneurysm in the right renal artery. The patient requested removal of the abdominal tumor since her ADL had deteriorated. We decided to perform a right nephrectomy with consideration of the left common iliac vein thrombus and right renal arterial aneurysm.As a precaution against pulmonary embolism in case the left common iliac vein thrombus dislodged, a retrievable inferior vena cava (IVC) filter was inserted before surgery. We were also concerned about possible rupture of the right renal aneurysm, so the right renal artery was embolized before surgery. After these procedures, a right nephrectomy was performed via a transperitoneal approach.The surgery was uneventful. The tumor weighed about 11 kg including 7,000 mL of bloody fluid. The IVC filter was removed the day after surgery, but the thrombus in the left common iliac vein remained, and an anticoagulant was started. Three months later, the thrombus had disappeared, and the anticoagulant was discontinued six months after surgery.According to the treatment guidelines for deep vein thrombosis, anticoagulants are the drugs of choice. IVC filters are seldom used to prevent pulmonary embolism. We initially administered an anticoagulant for the thrombus in the left iliac vein. However, an increase in abdominal tumor size suggested the drug had caused internal rebleeding and it had to be discontinued. Ultimately, we used a temporary retrievable IVC filter during the right nephrectomy with success.There is currently no consensus on when to use an IVC filter. Moreover, very little data exists on the use of an IVC filter during the perioperative period. Therefore, given the risk of potential thromboembolism, although we were able to use it successfully in our surgery, it should not be employed without a thorough benefit-risk assessment.