Selva Kabul

Objective: Endometrioid endometrial carcinoma (EEC) generally has a favorable prognosis, yet some cases exhibit aggressive behavior unexplained by standard parameters. Although p53 immunohistochemistry (IHC) primarily serves as a surrogate for TP53 mutations, quantitative variation within the wild-type (wt) category may hold prognostic value. This study investigated whether the proportion of p53-positive tumor cells correlates with established prognostic parameters in p53-wt EEC. Methods: Eighty-eight p53-wt EEC hysterectomy specimens (2022–2024) were retrospectively analyzed. Two pathologists independently evaluated p53 nuclear positivity percentages. Clinicopathological data, including grade, tumor size, myometrial invasion, cervical involvement, lymphovascular invasion (LVI), and microsatellite instability (MSI) status, were analyzed. An optimal cutoff for p53 expression was determined via Receiver Operating Characteristic (ROC) analysis. Results: p53 positivity ranged from 1% to 90%. ROC analysis identified a 4% cutoff, stratifying cases into low (≤4%, n=36) and high (>4%, n=52) expression groups. High p53 expression was significantly associated with LVI (p=0.0049), higher tumor grade (p<0.0001), and MSI-high status (p=0.0064). No significant associations were found with tumor size, myometrial invasion depth, or cervical involvement. Conclusion: In p53-wt EEC, higher p53 expression correlates with adverse clinicopathological features. Quantitative p53 IHC assessment may identify biologically distinct subgroups and provide complementary prognostic information in routine practice.

Synovial sarcoma is a rare malignant mesenchymal neoplasm that typically occurs in soft tissue sites, and the kidney is an uncommon primary location. Previous studies of primary renal synovial sarcoma are limited by small sample sizes, and our understanding remains incomplete. Here, we present the largest multi-institutional case series to date of primary renal synovial sarcoma, with a focus on novel and molecular findings. A total of 70 cases were contributed by multiple institutions. Comprehensive clinical and histopathologic data were collected and analyzed. The mean patient age was 40 years, with a male-to-female ratio of 1.9:1. The most common presenting signs and symptoms were pain and hematuria. The mean tumor size was 11.6 cm (range: 2.3 to 26 cm), with frequent cystic change and necrosis. The mean follow-up was 29 months (range: 2 to 129 mo), and the rates of metastasis, recurrence, and death due to disease were 62.7%, 33.3%, and 50.0%, respectively. Histologically, 56.1% were monophasic synovial sarcoma, 15.1% were biphasic, and 28.8% were poorly differentiated or showed round cell features. Molecularly, SS18::SSX2 fusion was detected in the majority of cases assessed (n=19), followed by SS18::SSX1 fusion (n=6) and a rare SS18::NEDD4 fusion (n=1). Given the morphologic and immunohistochemical overlaps with many other neoplasms, accurate diagnosis with preferably molecular techniques is crucial for appropriate prognostication and treatment of this aggressive tumor.

The differential diagnosis between pleural epithelioid mesothelioma and peripheral lung adenocarcinoma remains a significant diagnostic challenge for pathologists. This study aimed to evaluate the diagnostic efficacy of a multi-antibody immunohistochemical (IHC) panel comprising Napsin A, Caveolin-1, Type III Collagen, and Tenascin-X. While Napsin A and Caveolin-1 are established markers, the diagnostic utility of Tenascin-X and Type III Collagen remains less explored in the current literature. A retrospective IHC analysis was performed on 70 paraffin-embedded tissue blocks, comprising 35 lung adenocarcinomas and 35 epithelioid mesotheliomas, diagnosed between 2005 and 2014. The expression patterns of Napsin A, Caveolin-1, Type III Collagen, and Tenascin-X were evaluated and compared between the two groups. Napsin A showed high sensitivity for adenocarcinoma (94.3%) with minimal expression in mesothelioma (2.9%). Conversely, Caveolin-1 and Tenascin-X emerged as strong markers for mesothelioma, with positivity rates of 97.2% and 88.6%, respectively (p < 0.001). Although Type III Collagen was exclusively expressed in mesothelioma (17.1%) and absent in all adenocarcinoma cases, its low sensitivity limits its standalone utility. Significant statistical differences were observed between the two tumor types for all markers evaluated. Our findings suggest that a panel including Napsin A, Caveolin-1, and Tenascin-X significantly aids in the differential diagnosis of lung adenocarcinoma and epithelioid mesothelioma. While Tenascin-X provides valuable supplementary data, the clinical application of Type III Collagen is constrained by its low sensitivity. Integrating these markers into diagnostic protocols can enhance diagnostic accuracy, though further validation in larger cohorts is recommended.

Background: Infection and inflammation are key contributors to spontaneous preterm birth (PTB), but the relationship between genitourinary microbial colonization and placental inflammatory pathology across preterm subgroups remains unclear. Methods: In this case–control study, women with PTB were compared with gestational age-matched controls. Urine cultures, Mycoplasma/Ureaplasma screening, inflammatory markers, and placental histopathology were analyzed. Early (24–33 weeks) and late (34–36 weeks) preterm births were evaluated separately. Results: Clinical risk factors were more common in PTB cases (87.0% vs. 68.7%, p = 0.001), particularly PPROM and fetal growth restriction. Conventional urine culture positivity did not differ between groups. Mycoplasma/Ureaplasma colonization was more frequent in controls (41.2% vs. 15.4%, p < 0.001). Early PTB was strongly associated with placental inflammation, including higher rates of histological chorioamnionitis, composite inflammatory lesions, placental culture positivity, and elevated CRP compared with late PTB. Conclusions: Early PTB may represent a distinct infection-associated phenotype characterized by prominent placental inflammation, whereas late PTB demonstrates a weaker inflammatory profile.

Aims: Plasmacytoid urothelial carcinoma (PUC) is an aggressive morphological subtype characterized by discohesive single‐cell infiltration and frequent loss of epithelial adhesion. Although p63 is widely regarded as a reliable urothelial lineage marker in conventional urothelial carcinoma, its expression may be reduced or absent in plasmacytoid tumours, creating an important diagnostic pitfall. This multi‐institutional study aimed to characterize the clinicopathological and immunohistochemical profile of PUC, with particular emphasis on p63 immunoreactivity and its relationship to adhesion‐related markers and other diagnostically relevant immunophenotypes. Methods and results: A total of 93 cases initially diagnosed as PUC were retrospectively reviewed across multiple centres. After histopathological re‐evaluation, 70 confirmed cases were included. Immunohistochemical analysis was performed for p63, e‐cadherin, p120 catenin, TRPS1, HER2/Neu . The cohort comprised 70 patients with a median age of 66.5 years (IQR, 59.8–72.0) and a strong male predominance of 85.7% (60/70). Most specimens were obtained from transurethral resections (64.3%, 45/70) and radical cystectomy specimens (34.3%, 24/70). The median tumour size was 3.0 cm (IQR, 1.0–5.0), and the median proportion of plasmacytoid differentiation was 80% (IQR, 20–100). Morphologically, tumours were classified as classic plasmacytoid in 65.7% (46/70), pleomorphic in 22.9% (16/70) and desmoplastic in 11.4% (8/70). Concurrent variant histology was identified in 21.4% (15/70), most commonly micropapillary (12.9%, 9/70) and sarcomatoid (7.1%, 5/70) components. Lymphovascular invasion was present in 51.4% (36/70), and concomitant carcinoma in situ was detected in 35.7% (25/70). Immunohistochemically, p63 expression was retained in only 10.0% of tumours (7/70). HER2 membranous overexpression was observed in 58.6% (41/70), while loss of E‐cadherin expression was highly prevalent (84.3%, 59/70). Aberrant p120 catenin expression was common, with cytoplasmic localization in 72.9% (51/70) and complete loss in 17.1% (12/70). TRPS1 immunostaining was available in 54 tumours and was negative in 92.6% of evaluable cases (50/54). Conclusion: PUC demonstrates a distinctive immunophenotype characterized by frequent loss of p63 and disruption of the e‐cadherin/p120 adhesion complex. Recognition of p63 attenuation, together with adhesion‐related markers and HER2 status, provides a useful diagnostic framework for distinguishing this aggressive subtype from conventional urothelial carcinoma and its mimickers.

Background and Objectives: One of the most critical areas of measurement and evaluation in healthcare is pathological evaluation, especially intraoperative consultation. Studies conducted to identify sources of error in this field are usually one-sided; however, in evaluation processes with multiple sources of error, such as intraoperative consultation, generalizability theory can evaluate these sources of error simultaneously in a single analysis, thereby contributing to the field. In this study, the reliability of intraoperative and permanent histopathological evaluations of glial tumors was analyzed using generalizability theory to identify the sources of error in the observed evaluation inconsistencies. Materials and Methods: The study included 319 glial tumor cases that underwent intraoperative evaluation and were analyzed using generalizability theory. Three pathologists performed independent evaluations in two stages. Results: The reliability coefficient calculated for all cases was 0.9234 without radiological information and 0.9243 after learning the radiological information. The reliability coefficient was 0.8875 and 0.8989, respectively, in cases over 18 years of age, and 0.8845 and 0.9062 in cases under 18 years of age. These findings indicate that the addition of radiological information to the evaluation resulted in a slight increase in reliability, particularly in cases under 18 years of age. In all of our reliability assessments for different conditions, the highest variability was found to originate from the rater. Conclusions: The findings suggest that intraoperative evaluation demonstrates a high degree of reliability in the pathological assessment of glial tumors. When differences between the rater and the technique are evaluated together, it is observed that the rater has a more significant impact on reliability. While radiological information is generally considered a factor that increases reliability, it is partially more effective, especially in cases involving individuals under the age of 18, which highlights the importance of multidisciplinary data sharing in intraoperative diagnostic processes.

Background and Objective: Bladder cancer (BC) is the ninth most common malignancy worldwide. Squamous cell carcinoma (SqCC), a rare histological variant, accounts for approximately 2–5% of all BC cases. Compared to urothelial carcinoma, the predominant subtype, research on SqCC remains limited and shows inconsistent findings regarding prognosis. This study aimed to compare survival outcomes between patients with SqCC and those with pure urothelial carcinoma (PUC). Methods: This retrospective, observational study analyzed pathology reports from 2549 transurethral resections of bladder tumors and 632 cystectomies performed at our institution between 1 December 2010 and 31 December 2023. Following pathological re-evaluation, 33 patients with SqCC and 132 with PUC were identified. After 1:3 propensity score matching, 20 patients with SqCC and 58 with PUC were included in the final analysis. Demographic, clinicopathological features, and survival outcomes were compared between groups. Results: The median follow-up was 2.31 years (range: 0.17–13.50). No significant differences in baseline demographic or clinical characteristics were observed, except for the type of surgery. Kaplan–Meier analysis demonstrated no significant differences in disease-free survival (DFS; p = 0.961) or overall survival (OS; p = 0.847) between SqCC and PUC groups. Multivariate Cox regression analysis identified T stage, nodal involvement, and adjuvant chemotherapy (CT) as independent predictors of DFS, while sex and metastasis at diagnosis were significant predictors of OS. Conclusion: Survival outcomes (DFS and OS) did not significantly differ between patients with SqCC and patients with PUC. Prognosis was more closely associated with disease stage at diagnosis, sex, and adjuvant CT. Further large-scale studies are warranted.