Blue nevi: a case report and review of the literature.

Blue nevi can present clinically as blue, gray, brown, or black solitary nodules or plaques on the skin. Histologically, they represent collections of melanocytes and melanophages in the dermis. We present a case of a cellular blue nevus in a 55-year-old white man that presented as an enlarging blue-gray nodule on the right dorsal foot. These cases can be challenging both clinically and histologically because malignant melanoma or malignant transformation of a blue nevus should be considered. We review the various types of blue nevi and the literature.