Eccrine spiradenoma: a report of malignant transformation.

The authors report the case of a 21-year-old man who had malignant transformation within an eccrine spiradenoma involving the big toe. Although benign eccrine spiradenoma is not an uncommon cutaneous adnexal tumour, malignant change in this tumour is rare. To the authors' knowledge only 16 cases have been reported previously. Two histologically distinct components were seen in the tumour: typical eccrine spiradenoma, constituting a small part of the tumour, and carcinoma with areas of transition. The patient was treated by below-knee amputation and superficial inguinal node dissection. There was no evidence of recurrence 2 years after surgery.