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An inflammatory bowel disease (IBD) resembling ulcerative colitis in mice may be attributed to an abnormality in the interleukin-2 gene. These mice exhibit pathological responses characteristic of IBDs, which are categorized as ulcerative colitis and Crohn's disease. An analysis of molecular pathogenesis of the disease elucidates functional role of the immune system. A dysfunction in the immune response to antigenic stimulus results in ulcerative colitis. An abundance of activated T and B cells, enhanced immunoglobin secretion, anti-colon antibodies and disrupted expression of major histocompatibility complex molecules are characteristic features of a functionally altered immune system.

Abstract Introduction Epstein-Barr virus-positive mucocutaneous ulcer is a newly recognized clinicopathologic entity in the spectrum of Epstein-Barr virus-positive lymphoproliferative disorders. This entity is characterized by a self-limited, indolent course. Case presentation We report the case of a 74-year-old, type 2 diabetic man who presented with an ulceroinfiltrative skin lesion on the left side of his neck. Histological examination showed that the lesion consisted of large atypical cells, some with Hodgkin-Reed-Sternberg-like morphology, in the midst of reactive lymphocytes, plasma cells, eosinophils and histiocytes. The atypical cells were partially positive for CD45, CD20, CD79a, CD30, B-cell lymphoma 2 and latent membrane protein 1 (CS.1-4), and negative for CD15, B-cell lymphoma 6 and CD10. In situ hybridization for Epstein-Barr virus-encoded ribonucleic acid was positive. Two years before, the patient had been diagnosed with a self-limited subcutaneous abscess in the same anatomic area that healed after antibiotic therapy. Conclusion Older patients with positive Epstein-Barr virus serology may develop B-cell lymphoproliferations due to age-related immune suppression. Epstein-Barr virus-encoded ribonucleic acid testing and clonality analysis, eventually complemented with close clinical follow-up, should be performed for suspicious inflammatory lesions in older patients.

Abstract Introduction Cystic lesions of the upper abdomen normally develop from pancreatic tissue. The differential diagnoses include neoplastic and non-neoplastic lesions. Pseudocystic tumors that secondarily involve the pancreas are very rare and may lead to diagnostic pitfalls. Case presentation A 51-year-old woman and a 65-year-old man, both German, presented with abdominal cystic lesions suspected to be pancreatic pseudocysts. Both tumors were classified as gastrointestinal stromal tumors, epithelioid subtype. In one case, tumor origin in the gastric wall was confirmed by relaparotomy. In the other case, a point mutation in PDGFRalpha gene, exon 18 proved the diagnosis of gastrointestinal stromal tumor. The tumors were resected and both patients are still alive and disease-free. Conclusions The differential diagnosis of cystic lesions in the upper abdomen must include gastrointestinal stromal tumors with pseudocystic change. The origin of a large cystic gastrointestinal stromal tumor may be difficult to determine. Epithelioid tumor pattern, weak or absent KIT expression and detection of PDGFRalpha mutation are typical diagnostic parameters of gastric gastrointestinal stromal tumors.

Summary: Burkitt lymphoma (BL) is an aggressive B‐cell‐malignancy derived from germinal‐centre B‐cells. Curative therapy traditionally requires intensive immunochemotherapy. Recently, immuno‐oncological approaches, modulating the T‐cell tumour response, were approved for the treatment of a variety of malignancies. The architecture of the tumour‐infiltrating T‐cell receptor (TCR) repertoire in BL remains insufficiently characterized. We therefore performed a large‐scale, next‐generation sequencing study of the complimentary‐determining region (CDR)‐3 region of the TCRβ chain repertoire in a large cohort of all epidemiological subtypes of BL (n = 82) and diffuse large B‐cell lymphoma (DLBCL; n = 34). Molecular data were subsequently assessed for correlation with clinical outcome. Our investigations revealed an age‐dependent immunoprofile in BL as in DLBCL. Moreover, we found several public clonotypes in numerous patients suggestive of shared tumour neoantigen selection exclusive to BL and distinct from DLBCL regardless of Epstein–Barr virus and/or human immunodeficiency virus status. Compared with baseline, longitudinal analysis unveiled significant repertoire restrictions upon relapse (P = 0·0437) while productive TCR repertoire clonality proved to be a useful indicator of both overall and progression‐free‐survival [OS: P = 0·0001; hazard ratio (HR): 6·220; confidence interval (CI): 2·263–11·78; PFS: P = 0·0025; HR: 3·086; CI: 1·555–7·030]. Multivariate analysis confirmed its independence from established prognosticators, including age at diagnosis and comorbidities. Our findings establish the clinical relevance of the architecture and clonality of the TCR repertoire and its age‐determined dynamics in BL. [ABSTRACT FROM AUTHOR]

Abstract Background Molecular analyses of the c-kit and PDGFRα genes have contributed greatly to our understanding of the development of gastrointestinal stromal tumors (GISTs), but little is known about their malignant potential. The aim of our study was to evaluate cell cycle regulators as potential prognostic markers in GISTs. Methods We investigated 104 KIT positive GISTs from various tumor sites in immunoassays on CD34, Ki67 and particularly on P53, BCL-2 and Cyclin D1. The results were compared with tumor size, mitotic rate, proliferative activity, histological subtype, nuclear atypia and risk assessment according to Fletcher and Miettinen. Occurrence of metastases and survival were also taken into account. Results The expression of P53 was significantly correlated with high risk criteria towards malignancy and epithelioid differentiation in GISTs. Likewise P53 label correlated significantly with the established prognostic indicators: tumor size, mitotic rate, nuclear atypia and proliferative activity. Regarding the site of tumor presentation, P53 was not a decisive factor. BCL-2 and Cyclin D1 expression was not related to any of the prognostic indicators. Conclusion The present data identified P53 being a recommendable marker for predicting the risk of malignancy in GISTs. In addition, we found P53 significantly correlated with epithelioid tumor differentiation, independent of tumor site. BCL-2 and Cyclin D1, however, did not prove to be deciding markers for diagnosis and prognosis.

Abstract Background Human mastocytosis is a heterogenous disorder which is linked to a gain-of-function mutation in the kinase domain of the receptor tyrosine kinase Kit. This D816V mutation leads to constitutive activation and phosphorylation of Kit with proliferative disorders of mast cells in the peripheral blood, skin, and spleen. Most PCR applications used so far are labour-intensive and are not adopted to daily routine in pathological laboratories. The method has to be robust and working on such different materials like archival formalin-fixed, paraffin-embedded tissue (FFPE) and blood samples. Such a method is introduced in this publication. Methods The Kit point mutation Asp 816 to Val is heterozygous which means a problem in detection by PCR because the wild-type allele is also amplified and the number of cells which bear the point mutation is in most of the cases low. Most PCR protocols use probes to block the wild-type allele during amplification with more or less satisfying result. This is why point-mutated forward primers were designed and tested for efficiency in amplification of the mutated allele. Results One primer combination (A) fits the most for the introduced PCR assay. It was able just to amplify the mutated allele with high specificity from different patient's materials (FFPE or blood) of varying quality and quantity. Moreover, the sensitivity for this assay was convincing because 10 ng of DNA which bears the point mutation could be detected in a total volume of 200 ng of DNA. Conclusion The PCR assay is able to deal with different materials (blood and FFPE) this means quality and quantity of DNA and can be used for high-througput screening because of its robustness. Moreover, the method is easy-to-use, not labour-intensive, and easy to realise in a standard laboratory.

The article presents a study on investigation of the prognostic capabilities of Glasgow Prognostic Score (GPS)advanced stage classical Hodgkin lymphoma (cHL) as a complementary resource for risk stratification. Topics include treatment of patients with a chemotherapy regimen along with Clinicopathological characteristics; multivariate analysis along GPS incorporating Positron emission tomography (PET) and limitations of the study which include its sample size and retrospective design.

Double-hit lymphomas (DHL) with MYC and either BCL2 or BCL6 rearrangements are rare neoplasms with an aggressive clinical presentation and grim prognosis. Moreover, molecular characterization of DHL remains insufficient, and especially the role of TP53 pathway disruption is unknown. We employed a next-generation sequencing approach to investigate the mutational status of TP53 in DHL and correlated genomic data with immunohistochemical reactivity for p53. We identified TP53 mutations in MYC+/BCL2+ lymphomas at a frequency intermediate between diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma. Remarkably, TP53 mutations were particularly scarce in MYC+/BCL6+ lymphomas. Our findings indicate a significant difference between these two types of DHL at a molecular level with pathogenetic implications, as arguably, TP53 mutations inhibiting p53 mediated promotion of apoptosis pose a synergistic advantage in clonal evolution of cells with malignantly enforced overexpression of BCL2. Immunohistochemical staining appears to be a sensitive surrogate of TP53 mutation status with moderate specificity. [ABSTRACT FROM AUTHOR]