Eccrine porocarcinoma.

We describe a 78-year-old woman with eccrine porocarcinoma presenting a zosteriform appearance on the lateral upper part of the buttock. Erosion and bleeding were observed in the center of a 50 X 80 mm, erythematous indurated plaque with an elevated border. Posterior to the plaque, there was another erosive plaque, 50 X 20 mm in diameter, with peripheral induration overlaid by two reddish papules. Based on the previous reports of 21 patients with eccrine porocarcinoma in Japan, we discuss the relationship between the clinical pattern and lymph node metastasis. The pedunculated eccrine porocarcinoma has less tendency to metastasize to the regional lymph nodes than the nonpedunculated form.