Verrucous pseudonevoid melanoma.

A case of an unusual variant of malignant melanoma resembling a papillomatous dermal nevus is presented here. The lesion was initially diagnosed as a Spitz nevus, and recurred locally five months after excision. The features which distinguish this lesion from the more common types of benign dermal nevi include the architectural atypia of the melanocytes, with a tendency for continuous proliferation of single cells along the dermoepidermal junction, as well as the presence of cytologic atypia with large hyperchromatic nuclei and mitoses. Despite its seemingly innocent appearance, distinction of this low-grade variant of melanoma from its benign counterparts is of importance in order to avert the possibility of recurrence and potential metastases.