A Case of Multiple Eccrine Porocarcinoma with Stepping-Stone Distribution on the Foot

An 89-year-old woman had three tumors of several years' duration in a stepping-stone distribution on the dorsum of her right foot. The two larger ones were diagnosed histologically as eccrine porocarcinomas, and the smallest of the three shared many clinical similarities with them. Eccrine porocarcinoma is a rare malignant tumor. We describe this peculiar case in which three tumors developed in the same region and discuss how they might have occurred. It is most likely that the three tumors of this case originated from nevoid tumors, and that the individual lesions exhibited malignant changes.