A rare malignant blue nevus resected from the back of a 34-year-old Caucasian woman is reported. Histopathologic examination showed the presence of a CBN as well as MBN. The CBN elements of this lesion showed the characteristic prominent neural type fascicles intertwined with melanocytes. The deeper regions of this skin neoplasm showed considerable variation in histopathologic patterns. Metastascs to the axillary lymph nodes and multiple subdermal soft tissue sites, invasion of the underlying skeletal muscle, and several recurrences in the chest wall indicate that this neoplasm is malignant, though of a lower order than a malignant melanoma. The ultrastructural characteristics of neoplastic cells indicate that this neoplasm is of Schwann cell origin.