An Unusual Case of a Scrotal Porocarcinoma and Review of the Literature

Abstract

:Porocarcinomas are rare tumors derived from the acrosyringium and eccrine ducts, which most commonly occur on the lower extremities or head and neck region in older adults. Microscopically, they invariably demonstrate continuity with the epithelium, showing downgrowth of broad anastomosing bands with more infiltrative intradermal cords and nests of pleomorphic tumor cells with ductal lumina; an associated poroma may also be seen. We report an unusual case of a porocarcinoma arising on the scrotum of a 55-year-old man. Because of the extraordinary location and the presence of keratinizing squamous differentiation, distinction from a squamous cell carcinoma was particularly challenging. Close examination revealed the presence of a co-existing poroma, and immunohistochemistry revealed loss of YAP1 with diffuse nuclear expression of NUT in both the porocarcinoma and poroma components. This finding is particularly suggestive of a YAP1::NUTM1 fusion which has been reported to be highly specific for poroid neoplasms. Distinction of porocarcinoma from its mimics is important due to the frequent aggressive behavior of this neoplasm.

Strategic Approach to Heterogeneity Analysis of Cutaneous Adnexal Carcinomas Using Computational Pathology and Genomics

“…Anti-SOX9 antibody (1:100 dilution; clone H-90; Santa Cruz Biotechnology Inc., Santa Cruz, CA), anti-NUT antibody (1:100 dilution; clone C52B1; Cell Signaling Technology, Beverly, MA), anti-N–terminal region of YAP1 antibody (dilution 1:200; clone 2F12; Abnova, Taipei, Taiwan) and anti-C–terminal region of YAP1 antibody (dilution 1:200; clone D8H1X-XP; Cell Signaling Technology, Beverly, MA) were used. As to anti-N–terminal YAP1 antibody, diffuse nuclear expression of the N-terminal portion was considered significant whereas the absence of C-terminal portion expression was considered significant for anti-C–terminal antibody ( Hartsough et al., 2023 ; Russell-Goldman et al., 2021 ; Sekine et al., 2019 ). Epithelial antigen (clone Ber-EP4; Dako Omnis) were used to specify hair germ.…”