The potential malignancy of eccrine spiradenoma.

Eccrine spiradenoma is a rare, usually benign tumor, originating from cutaneous sweat glands. Its clinical and histologic diagnosis can be difficult at times, especially when malignant features are present. Proper management requires radical surgical excision. Two cases of spiradenoma are reported, one of which highly malignant with diffuse pulmonary metastases leading to the patient's death in spite of repeated radical surgery.