title: A distinctive type of widespread congenital melanocytic nevus with large nodules.
abstract: We report an unusual case of congenital melanocytic nevus presenting in a 19-year-old African woman as widespread papules and variably sized nodules and tumors affecting the entire body, including the palms, soles, and oral mucous membrane. Histopathologic examination of 3 representative skin lesions showed mainly dermal aggregations of round to oval, focally pigmented, monomorphous melanocytes, arranged in nodular and plexiform patterns. Scattered areas with spindle-shaped dendritic melanocytes surrounded by fibrosis were also noted in the center of the lesions. The clinical and histopathologic findings were similar to those in 2 other previously reported cases, except that in 1 of the earlier cases the skin nodules were composed of spindle-shaped cells, suggesting a type of blue nevus. The findings in our case indicate a broader spectrum of morphologic features in this condition, with dermal aggregations of melanocytes showing congenital features, representing a common histopathologic denominator. Based on this observation, we suggest the term "widespread congenital dermal nevus with large nodules" to be the most appropriate for this rare, but distinctive, type of congenital nevus.
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008544:Melanocytes / Q000473:pathology; D009508:Nevus, Pigmented / Q000151:congenital* / Q000473:pathology*