Longstanding Eccrine Syringofibroadenoma With Evidence of Carcinomatous Transformation

Eccrine syringofibroadenoma (ESFA) is a cutaneous proliferation of eccrine ducts, mainly encountered in association with other dermatoses or skin tumors. Although a benign condition, either considered as a hamartoma or a reactive hyperplasia rather than a real neoplasm, some evidence suggests that longstanding ESFA can undergo malignant change. The recognition of such opportunity could have important therapeutic implications. We present a case of ESFA showing areas of carcinomatous transformation, discussing its morphological and immunohistochemical findings.