Malignant combined nevus.

This report describes an example of combined nevus with malignant transformation. The clinical impression was blue nevus. Histologically, the lesion was composed of a cellular blue nevus in the reticular dermis and an overlying compound melanocytic nevus. The junctional component of the melanocytic nevus showed transition to malignant melanoma in situ. A review of the literature failed to find a precedent for the present case.