Human pathology最新文献

We report 31 cases of follicular lymphoma (FL) with signet ring (SR) cells, representing < 0.05% of FLs diagnosed at our institution. The cohort includes 16 women and 15 men with a median age of 65 years (range, 26-87). All patients presented with lymphadenopathy. Twenty-three (74%) patients had advanced stage disease and 8 (26%) had localized (stage I or II) disease. Twenty-one (68%) patients underwent excisional biopsy, 8 core needle biopsy and 2 fine needle aspiration. All 29 neoplasms with biopsy specimens had a follicular pattern, at least in part, but 9 (25%) had diffuse areas. These neoplasms were grade 1-2 in 19 cases and grade 3A in 10 cases. In addition, 1 patient had FL grade 1-2 in the nasopharynx and FL grade 3A FL in a regional lymph node and 1 patient had FL grade 3A (25%) associated with diffuse large B-cell lymphoma (75%). We semi-quantified the percentage of SR cells as follows: 5-10% in 2 cases, 11-25% in 10, 26-50% in 7, 51-75% in 10 and >75% in 1 neoplasm. Immunophenotypic analysis using immunohistochemistry was performed in all cases and flow cytometry immunophenotypic analysis was performed in 24 cases. All neoplasms were positive for pan-B-cell markers and lacked T-cell antigens. CD10 was positive in 28 of 30 cases, and BCL2 and BCL6 were positive in all 20 and 18 cases assessed, respectively. IGH::BCL2 was detected in all 10 cases tested by fluorescence in situ hybridization. Targeted next-generation sequencing analysis performed successfully on 4 cases identified recurrent mutations in genes often involved in FL, such as KMT2D and TNFRSF14. In conclusion, in this retrospective study we provide the largest case series of FL-SR. We show that SR cells can be numerous in FL, but otherwise these cases resemble classic FL. We also provide results of next generation sequencing data on 4 cases which heretofore has not been reported.

Bladder paraganglioma is an exceptionally rare neuroendocrine tumor with important diagnostic and prognostic implications. We retrospectively analyzed 110 bladder paragangliomas diagnosed between 2000 and 2025 to better characterize clinicopathologic features, immunophenotypic patterns, and clinical outcomes, with particular emphasis on S100, SOX10, and SDHB immunohistochemistry. The cohort showed a slight female predominance (F:M = 1.34) and a mean age at diagnosis of 62.7 years. Most tumors involved the muscularis propria, supporting a bladder wall origin. Among cases with available S100 staining, nearly half (48.5%) demonstrated diffuse, strong S100 expression in both chromaffin and sustentacular cells, an unusual pattern that frequently caused diagnostic confusion and was the reason for consultation. In contrast, SOX10 expression remained restricted to sustentacular cells in all tested tumors, underscoring its reliability as a Schwannian marker. Loss of SDHB expression was identified in 14.5% of tumors and was significantly associated with younger age, male sex, absence of diffuse S100 expression, and metastatic disease. All S100-positive tumors retained SDHB expression. Among patients with available follow-up, 20% developed metastatic disease, with a 5-year metastatic rate of 38.5%; most metastatic tumors showed SDHB loss and were S100-negative. No paraganglioma-related deaths were documented. These findings demonstrate that diffuse S100 positivity in bladder paraganglioma is relatively common and represents a significant diagnostic pitfall. Importantly, S100-positive tumors appear to be associated with intact SDHB expression and a potentially less aggressive phenotype, whereas SDHB loss identifies a higher-risk subset with increased metastatic potential.

Background: Focal active colitis (FAC) is a histopathologic finding characterized by focal neutrophilic crypt injury without chronic architectural changes. Its clinical implications, particularly its association with inflammatory bowel disease (IBD), remain debated.

Methods: We retrospectively reviewed colorectal biopsies diagnosed as FAC (2005-2024) at a tertiary center in Lebanon. Adult patients (>18 years) with isolated FAC and available clinical follow-up were included. Clinical outcomes, endoscopy, and subsequent diagnoses were analyzed.

Results: 419 patients had complete follow-up data. Mean age was 52.5 years; 51.5% were female. Abdominal pain was the most common presentation (57.5%). Colonoscopy was normal in 73%. During a mean 26-month follow-up, 9 patients (2.15%) developed IBD (4 Crohn's disease, 3 ulcerative colitis, 2 unclassified). IBS was diagnosed in 33.2%, infectious colitis in 11.2%, drug-induced colitis in 8.6%, diverticular disease in 4.5%, and ischemic colitis in 0.7%. 25.3% had no identifiable etiology with negative follow-up. FAC was incidental in 10.5% and persistent in 3.8%. No histologic features predicted progression to IBD.

Conclusion: In this 19-year, 419-patient study, FAC was most often linked to IBS, infection, or drug-induced injury, with only 2.15% progressing to IBD. No predictive histologic features were identified. FAC remains a nonspecific finding; careful follow-up is warranted in symptomatic patients, while incidental cases are usually clinically insignificant.

Introduction: Struma ovarii is a rare type of ovarian teratoma consisting predominantly of thyroid tissue and showing a usually benign clinical course which cannot be predicted by its histology. Thus, their molecular analysis could help to better classify these tumors. However, the molecular profile of struma ovarii, especially the benign one, has been rarely studied.

Material and methods: We performed a retrospective, non-interventional study of 23 benign ovarian struma ovarii using formalin-fixed paraffin-embedded tissues for DNA extraction and next-generation sequencing.

Results: Two tumors harbored interesting molecular alterations. The first second tumor, diagnosed in an adult patient, harbored two DICER1 variants: c. 4738 C>T and c. 5429 A>T. The second last one was a struma ovarii harboring a POLD1 c.961G>A, p.(Gly321Ser) variant. None of the tumors harbored BRAF mutations.

Conclusion: Benign struma ovarii do not harbor BRAF alterations. DICER1 and POLD1 variants need further investigation in this tumor pathology.

Four important challenges in liver pathology are explored. Recognizing challenges in diagnostic pathology is one of the most important ways the field grows and improves, and this is reflected in the four challenges selected for review. The first problem considers the best approach to low-grade hepatocellular lesions in livers with chronic vascular disease. The second problem addresses the difficulties in making a diagnosis of portal vein disease and in choosing the best nomenclature. Problem 3 focuses on best practices for primary carcinomas of the liver that are difficult to classify as hepatocellular carcinoma versus cholangiocarcinoma. Problem 4 discusses the good and the bad of ongoing efforts to change established names of disease entities. All of these problems are discussed in their historical contexts and emphasize the practical aspects relevant to surgical pathology.