p16 Expression in Multinucleated Stromal Cells of Fibroepithelial Polyps of the Anus (FEPA): A Comprehensive Review and Our Experience

Fibroepithelial polyps of the anus (FEPA) are a common benign polypoid proliferation of the stroma covered by squamous epithelium. They are also an often-overlooked part of pathological practice. Currently, immunohistochemistry (IHC) for p16 is the only recommended test for anal intraepithelial neoplasia, but the expression of p16 in stromal multinucleated atypical cells in FEPA has not been described. We aimed to evaluate the expression of p16 in stromal multinucleated atypical cells in FEPA and its role as a diagnostic biomarker to determine the origin of the atypical multinucleated cells in the stroma of FEPA and to rule out the possibility of a neoplastic process. Therefore, we researched a series of 15 FEPA in middle-aged patients histologically and by IHC. Examination of the subepithelial connective tissue from the FEPA showed bizarre, multinucleated cells, while their causal relationship with human papillomavirus (HPV) infection was rejected. In all cases, these cells showed mild to moderate atypical nuclear features and positive expression for p16, while the overlying squamous epithelium was negative. We concluded that FEPA are benign lesions in the stroma where mononuclear and multinucleated (sometimes atypical) cells showing fibroblastic and myofibroblastic differentiation can be found. Nevertheless, we believe that these cells have a practical diagnostic significance, although sometimes the presence of giant cells is difficult to establish, especially in the inflammatory context. The histological similarity between FEPA and normal anal mucosa supports the hypothesis that FEPA may represent the reactive hyperplasia of subepithelial fibrous connective tissue of the anal mucosa

PD-L1 positive lympho-epithelial lesions in inflammatory prostate

Objectives. Ductal epithelial changes (lympho-epithelial lesions-LEL) in prostatic chronic inflammation (CI) are not well studied so far. Aim. To investigate LEL immediately adjacent to prostatic CI. Methods. We studied LEL in 144 prostatic surgical and autopsy specimens in various types of prostatic CI: NIH-category IV prostatitis (histologic prostatitis-HP), nonspecific granulomatous prostatitis (NSGP), and the reactive lymphoid infiltrates in the vicinity of benign prostatic hyperplasia (BPH) and prostate adenocarcinoma (PCa). CI is scored as low and high grade (LG, HG) according to the severity of inflammation. Results. LEL was identified in all types of prostatic specimens and in all types of prostatic CI: in 70.9% of patients with HP; in 100% of cases with NSGP; in 68.7% and in 80% adjacent to BPH and PCa respectively. Statistical analysis showed a significant correlation of the presence of LEL with HG CI (p<0.001). LEL showed strong membranous PD-L1 expression. Conclusions. The study presents the first attempt to examine LEL in inflammatory human prostate. PD-L1 positive LEL have no diagnostic organ specificity, although they are a constant histological finding in HG prostatic CI. LEL, inducible after birth by CI, are an integral part of prostate-associated lymphoid tissue (PALT) and of the inflammatory prostatic microenvironmen

Nonspecific granulomatous prostatitis in association with eosinophilic epithelial metaplasia and prostatic adenocarcinoma

We present the first case of nonspecific granulomatous prostatitis (NSGP) associated with both eosinophilic epithelial metaplasia (EM) in benign glands and prostatic adenocarcinoma (PCa). The patient was a 68-year old man with a history of obstructive prostatic syndrome. After a transurethral resection of the prostate, the histologic analysis revealed NSGP and PCa. EM was seen in benign peri-granulomatous secretory epithelial cells as PAS Diastase positive granular eosinophilic transformation of the apical cell cytoplasm. This unusual cell appearance closely simulated the Paneth cell-like changes found in PCa. Negative chromogranin expression and weakly positive P504S immune staining in the foci of EM, surrounded by P63 positive basal cells confirmed the benign EM - phenotype. The combination of NSGP with both EM and PCa has not been reported in medical literature so far. Some observations concerning their differential diagnosis are suggested