Ganglioneuromatous tumor of the skin: a combined heterotopia of ganglion cells and hamartomatous neuroma: report of a case.

We report the histologic and ultrastructural findings of a solitary, unusual cutaneous tumor in a 69-year-old woman. The tumor is characterized by many mature ganglion cells in the papillary dermis and fascicles of unmyelinated axons in the lower dermis. The lesion is ganglioneuromatous but differs from the other ganglioneuromas histologically in that the ganglion cells do not intermingle with the neuromatous elements. It may represent a combined heterotopia of ganglion cells and hamartomatous neuroma. The histologic differential diagnosis and the possible pathogenesis are discussed.