Eccrine porocarcinoma.

Eccrine porocarcinoma (EPC) is a rare cutaneous neoplasm that grows slowly over a long period of time but often experiences an accelerated growth phase. This malignant tumor may arise denovo or evolve from a pre-existing benign eccrine poroma. Histologic evaluation demonstrates anaplastic cells involving the epidermis and infiltrating the dermis. Metastasis to regional lymph nodes distally occurs in a significant number of cases. Treatment modalities have included standard excision, Mohs micrographic surgery (MMS), chemotherapy, and radiation therapy. Recently sentinel lymph node biopsy has begun to be investigated as a staging tool. The literature on EPC is reviewed with attention paid to which of the various therapeutic options offers a clear advantage over the others. MMS affords the greatest likelihood of clear margins and cure in absence of regional and distant metastases.