Atypical fibroxanthoma masquerading as xanthogranuloma

Atypical fibroxanthoma is an uncommon spindle cell tumor that has a clinically benign course despite the presence of bizarre xanthoma cells. A 90-year-old female presented with a 2-month history of an ulcerative plaque on the right cheek. The initial punch biopsy revealed a benign histological appearance with prominent xanthomatous cells, but the specimen excised afterwards showed malignant features with a spindle and epithelioid cell proliferation with pleomorphism and atypia. The tumor cells stained positively for vimentin and CD68, they were partially positive for CD99 and CD10 and they were negative for CD34, S100, p63, desmin and actin. We report here on a case of atypical fibroxanthoma masquerading as xanthogranuloma.