Primary eccrine porocarcinoma of the finger with transit forearm and axillary metastasis.

Sweat gland tumors of the upper extremity are uncommon. Eccrine porocarcinoma is a rare skin malignant lesion representing 0.005% to 0.01% of all cutaneous tumors, which most commonly presents in patients more than 60 years of age. Approximately 250 cases of eccrine porocarcinoma have been reported since this disease was first described in 1963. However, only 2 cases occurring specifically on the finger (including the current case) have been documented in the literature to date. On the basis of the rarity of eccrine porocarcinoma of the finger, we report an eccrine porocarcinoma that presented as an ulcerated lesion of the left ring finger with metastasis to the forearm and axilla in an 80-year-old man. The etiology, diagnosis, treatment, and prognosis of this disease are discussed, with a brief review of the literature.