Merkel cell carcinoma (MCC) is a rare, aggressive neuroendocrine skin carcinoma. The pathogenesis involves Merkel cell polyomavirus (MCPyV) and ultraviolet radiation exposure. Studies on MCC in Turkey are scarce, with essential data on local etiopathogenic and prognostic factors still lacking. We aimed to analyze the clinical and histopathologic features, biomarkers, and to evaluate these findings alongside Turkish literature to infer the etiopathogenesis, prognosis, and possible treatment options for the disease. We analyzed the clinicopathologic features of 7 MCC patients diagnosed at the Pathology Department of Pamukkale University between 2003 and 2024 in this retrospective study. Clinical data was retrieved from the hospital’s electronic records. Formalin-fixed, paraffin-embedded tumor specimens stained with hematoxylin-eosin were examined microscopically. MCPyV, Retinoblastoma 1 (RB1), p53, PRAME, PD-L1, and MMR proteins were evaluated immunohistochemically. Research on MCC from Turkey was sourced from Turkish databases (ULAKBIM, Turkiye Atif Dizini, DergiPark, Turk Medline) and international databases (Pubmed, Google Scholar, Scopus, Embase). The literature review identified original research, case reports, theses, and conference presentations. The patients in our series, all aged over 50 (mean age 76.1 ± 14.8), with a slight predominance of one gender (F: M = 1.33:1). During a mean follow-up of 16.1 months, 42.9% (3/7) had lymph node metastases, and 57.1% (4/7) showed distant metastases. PRAME was positive in 42.9% of the cases (3/7). The total number of MCC cases reported from Turkey was estimated at 227 ± 46, with MCPyV status available in a subset, showing a positivity rate of 70.3%. PD-L1 expression was observed in the tumor microenvironment in 55% of virus-positive MCC cases from Turkey. The 9% incidence of gluteal localization in Turkish MCC cases, considering its geographical significance, is noteworthy. Notably, all MCC cases from Turkey in which microsatellite instability status has been assessed were found to be microsatellite stable. PRAME should be investigated in larger series for its potential role in the shared oncogenic pathways of MCC.

To evaluate the value of multimodal ultrasonography (US) in a rat experimental torsion model after 6 h of torsion with different degrees. Twenty-one male rats were divided into three groups. Left testes of the rats were twisted around their vascular pedicle 360 degrees in group 1, 720 degrees in group 2, and 1080 degrees in group 3 and intact right testes of the rats were accepted as control group. Grey-scale US, superb microvascular imaging (SMI), colour Doppler ultrasonography (CDUS), strain elastography (SE), and two-dimensional (2-D) shear wave elastography (SWE) examinations were applied 6 h after torsion procedure and testes were removed for pathological evaluation. Short-axis dimensions and volumes of the torsion side were higher than control testes. Lengths of the testes in the 3rd torsion group were smaller than the testes in groups 1 and 2 (P < 0.002). SMI was better than CDUS in recognizing blood flow in testicular tissue. Strain ratios were higher in group 1 and decreased with the increasing torsion degree. Emean and standard deviation (SD) measurements increased in the torsion side. Pathologically the mean testicular damage scores were statistically significant between torsion and control testes in all groups. Our results showed that short-axis and volume measurements, SMI, 2D-SWE, and SE are effective in the evaluation and diagnosis of testicular torsion (TT). Evaluation of affected testis and intact testis with multiparametric US in late presenting TT cases is more reliable than being dependent on a single sonographic modality.

Systemic sclerosis (SSc) is an uncommon rheumatic disease in which the underlying main histopathologic feature is a thickening of the skin due to excessive accumulation of collagen in the extracellular tissue. Fibrogenesis, chronic inflammation, and ulceration may eventually promote skin neoplasms. Although nonmelanoma skin cancer (NMSC) is the most frequent type, there have been restricted case reports and case series with skin cancers in SSc patients in the literature. Herein, we describe a 78-year-old woman diagnosed with diffuse cutaneous systemic sclerosis thirteen years ago and associated nonspecific interstitial pneumonia that was successfully treated with high cumulative doses of cyclophosphamide. She developed basal cell carcinoma and squamous cell carcinoma of the skin in the follow-up. She is still on rituximab treatment with stable interstitial lung disease as indicated by pulmonary function tests and high-resolution chest computed tomography. To our knowledge and a literature search, this is the first reported patient with SSc with two types of skin cancer. In this review, we also aimed to emphasize the relationship between SSc and skin cancer, and possible risk factors for SSc-related skin cancer.

Solid pseudopapillary neoplasms (SPNs) are rare pancreatic tumors that are indolent but occasionally present with metastatic or locally invasive disease. Although recurrent CTNNB1 exon 3 mutations define their molecular background, the clinicopathological and molecular features associated with these less common presentations remain incompletely characterized. This retrospective study included 62 patients diagnosed with SPN between 2000 and 2025. Clinicopathological and immunohistochemical features, including β-catenin, progesterone receptor (PR), androgen receptor (AR), and BAP1, were evaluated. Targeted sequencing was performed in a subset of cases with metastatic or locally invasive disease (n = 5). Patients showed a wide age range (8–71 years), female predominance (54/62, 87.1%), and a mean tumor size of 7.2 cm. Lymphovascular invasion was rare (1/59, 1.7%). Metastatic or locally invasive SPNs (n = 8) more frequently showed higher Ki-67 values (median, 5%; range, 1%–15%), increased mitotic activity (2/8, 25%), and capsular/parenchymal invasion (6/8, 75%), while perineural invasion was absent. All tumors demonstrated nuclear β-catenin expression, with PR and AR positivity (50/59, 84.7% and 47/57, 82.5%, respectively). PR expression was higher in AR-positive cases (43/47, 91.5% vs. 6/10, 60%). BAP1 loss was identified in 13/57 cases (22.8%). Targeted sequencing consistently identified CTNNB1 exon 3 mutations. Additional low-frequency molecular alterations affecting genes involved in cell cycle regulation, chromatin remodeling, and signaling pathways, including CDKN2A and BAP1 , were observed. During a mean follow-up of 97.2 months, distant metastasis occurred in 4/62 patients (6.5%) and locally invasive disease in 4/62 (6.5%), with an overall survival rate of 95%. Overall, these findings highlight the biological heterogeneity of SPNs and indicate that, despite a shared molecular background, aggressive behavior is not defined by a single reproducible pathological or molecular feature.

Preferentially expressed antigen in melanoma (PRAME) expression has been described in Merkel cell carcinoma (MCC), but its clinicopathologic and biological significance remains incompletely characterized. We investigated PRAME expression in MCC and its relationship with Merkel cell polyomavirus (MCPyV) status, PD-L1 expression, tumor-infiltrating lymphocytes (TILs), clinicopathologic features, and clinical outcome. Thirty-five MCC cases from 3 centers were retrospectively reviewed. Histopathologic features and immunohistochemical expression of PRAME, PD-L1, MCPyV, and p53 were reassessed. PRAME positivity was defined as staining extent scores of 3+ or 4+ combined with at least moderate staining intensity. TILs were evaluated on hematoxylin and eosin sections. Clinicopathologic correlations were assessed statistically, and overall survival and distant metastasis-free survival were analyzed using Kaplan-Meier and Cox regression methods. PRAME expression was identified in 10 of 33 evaluable tumors (30.3%). Most positive cases showed diffuse nuclear staining, although one tumor demonstrated heterogeneous PRAME expression. MCPyV positivity was seen in 51.4% of cases, and PRAME expression was more frequent in MCPyV-positive tumors ( P =0.057). Combined PRAME/PD-L1 positivity was associated with higher TIL density ( P =0.018). PRAME expression was not associated with clinicopathologic parameters or survival. Lower PD-L1 expression (CPS <1) was independently associated with shorter overall survival. PRAME was expressed in approximately one-third of MCCs. PRAME expression was not independently associated with survival outcomes. Higher expression rates in MCPyV-positive tumors and associations with selected immune-related parameters warrant further investigation.

Introduction Inflammatory fibroid polyp (IFP) is seen in the gastrointestinal tract. In most cases, somatic mutations in PDGFRA gene were observed and the true neoplastic origin of this entity was understood. It is a benign mesenchymal tumor and rarely recurs. The aim of the study was to reveal the histopathologic features of our IFP cases and to investigate the risk of cancer in one case. Materials and Methods We performed a retrospective clinicopathological analysis of patients (n=12) who were reported as IFP between 2012 and 2022. Formalin-fixed, paraffin-embedded and hematoxylin-eosin (H&E)- stained slides of the cases were re-examined by two pathologists microscopically. Results All patients were adults and ranged in age from 30 to 85. Male to female ratio was 1:2. One polyp was localized in small intestine, one in colon, and the others in stomach. Histologically, there were hyperplastic epithelial changes (7/12), low-grade (3/12), and high-grade dysplasia (1/12) accompanying IFPs. One case was associated with early gastric adenocarcinoma. Discussion Although IFP appears as a benign mesenchymal tumor, it should be kept in mind that dysplasia and rarely carcinoma may accompany this lesion. Larger case series are needed to elucidate the mechanisms of dysplasia and carcinoma development associated with IFP.