Dematiaceous fungal infections: clinical and pathologic conundrums.

Dematiaceous fungi are defined by pigment within their cell walls. They are increasingly recognised human pathogens, causing a wide range of clinical presentations, from localised subcutaneous infections to disseminated disease in rare cases. We report our institutional experience with diagnosis of dematiaceous fungal infections from 2005 to 2022 and highlight four instructive cases that clinically and pathologically mimicked other diseases for which the diagnosis was confirmed by fungal culture (one case) or supported by PCR with 28S rRNA and internal transcribed spacer primers (three cases).

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

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.