A Case of Subungual Reactive Eccrine Syringofibroadenoma

Eccrine syringofibroadenoma (ESFA) is a rare eccrine tumor. We report the case of a 70-year-old woman who had presented a pincer nail deformity on the toes for 55 years and a left painless subungual tumor for 2 years. Histologic examination revealed branching anastomosing strands of epithelial cells with ductal structures in a fibrovascular stroma. The luminal cells showed positive staining for carcinoembryonic antigen, as in acrosyringeal cells and cells of dermal ducts. To our knowledge, our case is the first with a subungual location. In the context of chronic trauma due to a pincer nail, it may be classified in the reactive subtype recently described.