Spiradenocarcinoma: morphological and immunohistochemical features

Malignant transformation of spiradenoma is a very rare event and its biologic features have not been fully described. Clinically, these tumours are characterized by the rapid enlargement of a long-standing cutaneous nodule. Microscopic examination discloses the presence of the two components, benign and malignant, whose morphological distinction is not always easy. We report the occurrence of a spiradenocarcinoma within a pre-existing spiradenoma of the cheek in a 48 year old man and review the previously reported cases especially on the basis of their morphological and immunohistochemical characteristics.