Pheohyphomycosis skin nodule in a young woman

We present a 28 year-old woman with a five-year history of an asymptomatic slowly growing 10 mm nodule on her right thigh, with clinical features suggestive of either a dermatofibroma or a keloid. The nodule was excised, and histopathological examination revealed prominent dermal granulomas containing numerous giant cells, focal microabscesses, abundant pigmented yeasts with dark walls –some arranged in chains–, and septate hyphae with blackish walls, findings initially suggestive of chromoblastomycosis. The abundance of moniliform hyphae arranged in linear chains allowed us to diagnose cutaneous pheohyphomycosis without hypodermal invasion. We highlight the chronic nature of the condition, its localized presentation, and the prominence of granulomas rich in giant cells –with scarce abscesses– as notable findings. The patient’s clinical course remains unknown, as she did not return for follow-up.