Eccrine porocarcinoma is a potentially fatal form of sweat gland carcinoma, due to its propensity to metastasize through lymph vessels. The authors report the case of a 69-year-old female who presented with swelling of the right leg and an ulcerated lesion of the right great toe. The initial histologic diagnosis was invasive squamous cell carcinoma. On follow-up, the patient developed lymphangitic tumor spread in the right leg, associated with right inguinal lymphadenopathy and lesions in vulva and flank. Reevaluation of the toe lesion led to a revised diagnosis of eccrine porocarcinoma. The patient also had 2 basal cell carcinomas of the multicentric/superficial type in the skin overlying the left breast. Past history included chronic ingestion of liquore arsenic (Fowler’s solution) in early adulthood as treatment for dermatitis herpetiformis.