Pancreatic ductal adenocarcinoma differs from other solid tumors with its unique immunosuppressive microenvironment and non-immunogenic feature. There are not many studies in the literature investigating the effect of these features on prognosis. To investigate the prognostic value of tissue-resident memory T cells, tumor microenvironment features, and tumor-associated immune cells in resected pancreatic ductal adenocarcinomas. Retrospective cross-sectional study. Of 138 patients diagnosed with pancreatic ductal adenocarcinoma between 2011 and 2018, 81 were included in the study. Specimens from operated patients were reassessed separately as peritumoral and intratumoral areas for tissue resident memory cells and tumor microenvironmental elements (tumor infiltrating lymphocytes, tumor stroma, CD204+ macrophages, PDL1+ immune cells). Disease-free survival and overall survival were defined from the date of operation to the date of recurrence and the date of first diagnosis to the date of death, respectively. If the patient was alive, the last visit date was taken into account. The median age at diagnosis was 63 (range: 40-78). The median follow-up period was 18.9 months (range: 1.4-80.4 months). Median overall survival was 23.7 months (1.4-80.4 months) and median disease-free survival was 10.8 months (1.4-74.4 months). Patients with higher intra-tumoral tissue-resident memory cell counts had a longer survival trend than those having lower values (25.6 months vs. 18 months, respectively, P = .84). According to microenvironmental evaluations, lower stromal score (defined as stroma having less desmoplasia and rich in cells) and presence of peritumoral Crohn’s-like inflammatory response were associated with higher survival (29.2 months vs. 19.7 months for low vs. high stromal scores, respectively, P = .16 and 30.2 months vs. 18.1 months for the presence of Crohn’s-like inflammatory response P = .13). Decreased survival was observed in tumors with increased CD204+ tumor-associated macrophages which were immunosuppressive elements of the microenvironment (12 months vs. 26.3 months for intra-tumoral assessment, P = .29). Tissue-resident memory T cells and other microenvironmental features may be prognostic in resectable pancreatic ductal adenocarcinomas. Further studies with larger cohorts are needed for validation.

Background/aims: Necrosis is an important pathological feature that reflects high malignancy potential in tumors such as hepatocellular carcinoma and renal cell carcinoma. We aimed to elucidate the prognostic impact of necrosis in ampullary carcinomas. Materials and methods: We reviewed 101 consecutive cases of ampullary carcinoma for tumor necrosis, types of necrosis, macroscopic and microscopic histopathological subtypes, lymphatic-vascular-perineural invasions, and other histopathological parameters. Results: Tumor necrosis was present in 19 (18.8%) cases and was identified as an independent poor prognostic indicator in multivariate survival analysis (p = 0.029). Conclusion: The presence of necrosis in ampullary carcinomas is directly related to vascular and perineural invasion and is a poor prognostic indicator independent of tumor stage. Including the presence of necrosis in the pathology reports of ampullary carcinomas will facilitate risk stratification.

Purpose: In the 2021 World Health Organization (WHO) classification, ependymomas were classified according to their anatomical localization and molecular features. The “RELA fusion‐positive ependymoma” group, which was the first defined molecular subtype in the previous (2016) classification, was included as “ZFTA fusion‐positive ependymoma” in the final classification. We aimed to determine ZFTA fusion‐positivity in supratentorial (ST) and posterior fossa (PF) ependymomas and to investigate the correlation with both L1CAM and p65 immunoreactivity. Methods: The study included 17 ST and 9 PF cases with Grades 1, 2, and 3 ependymomas. The presence of the ZFTA fusion was evaluated using the fluorescence in situ hybridization (FISH) technique. L1CAM and p65 antibodies were applied for immunohistochemical analysis. The immunoreactivity for L1CAM and p65 was correlated with ZFTA fusion as assessed by FISH. Prognostic significance of the same was evaluated using the Kaplan–Meier survival analysis. Results: ZFTA fusion‐positivity was detected in 7 of 12 (58%) ST‐localized Grade 3 ependymoma cases; however, it was not observed in PF‐localized cases or in ST‐localized Grade 1 subependymoma (SE) and Grade 2 ependymoma cases. Six of the seven ZFTA fusion‐positive cases exhibited clear cell morphology. All ZFTA fusion‐positive cases showed L1CAM immunohistochemical positivity, and six of them also demonstrated nuclear p65 positivity. Moreover, we identified a new FISH pattern, which we termed the “short break‐apart.” Conclusion: Together, these data indicate a strong correlation between FISH and immunohistochemistry results. However, a more reliable assessment on this matter could be accomplished through a multicentric study involving a larger number of cases.

Objective: Preoperative identification of familial pheochromocytoma and paraganglioma (PPGL) is crucial, yet often overlooked, leading to missed diagnoses. Typically, succinate dehydrogenase-B (SDHB) and fumarate hydratase (FH) tests are applied postoperatively to confirm familial links and assess prognosis. However, routine preoperative multidisciplinary collaboration is limited, causing delayed screening requests. Consequently, routine SDHB and FH immunohistochemistry (IHC) testing is not widely practiced. This study introduces SDHB fluorescence in situ hybridization (FISH) as a diagnostic tool, akin to HER2 IHC-FISH testing in gastric carcinomas. Materials and Methods: Succinate dehydrogenase-B and FH IHC were conducted on 43 cases. FISH analysis was performed for 28 cases with suspected familial origin or SDHB IHC loss to determine whether the protein loss was due to chromosomal changes. Results: Complete SDHB IHC loss occurred in 8 cases, partial loss in 4, and preservation in 31. Complete FH loss occurred in 10 cases. FISH analysis revealed chromosomal breaks in 20 cases (71.4%), including those with SDHB/FH IHC loss or positive clinical history. Ten cases (35.7%) showed a “red-signal only” pattern, suggesting further genetic testing. Conclusion: Succinate dehydrogenase-B FISH serves as a cost-effective tool for early PPGL diagnosis, complementing SDHB and FH IHC results. It can help identify cases that need genetic testing, even when IHC results are preserved.