Neurotropic melanoma of the lower lip.

The neurotropic melanoma is a rare and highly malignant variant of melanoma that possesses a biphasic neoplastic component. A lentigo maligna melanoma commonly precedes a downgrowth of spindle cells that exhibit fascicle formation and striking neurotropism. A strong predilection for occurrence on the lip has been indicated by published reports. Difficulties exist in the initial diagnosis of the tumor because of its biphasic growth pattern, while the biologic behavior of the tumor is that of multiple recurrences, perineural metastases with cranial neuropathies and intracranial disease, and regional and distant organ metastases. The clinical and histopathologic features of a neurotropic melanoma of the lip are shown, and a brief review of the histogenesis, treatment, and prognosis are presented.