The ringlike pattern in vulvar melanosis: a new dermoscopic clue for diagnosis

Vulvar melanosis is a benign pigmented lesion that may clinically mimic melanoma. Whereas the dermoscopic features of other pigmented skin lesions have been extensively described, little is known about vulvar melanosis.

A retrospective dermoscopic study was conducted on 87 lesions with histopathologically proved melanosis. We describe and define, for the first time to our knowledge, a ringlike pattern, found in 28 of 87 melanotic lesions (32%), characterized by multiple round to oval structures, white to tan, with dark brown, well-defined regular borders. The structureless and globularlike patterns were observed in 18 of 87 lesions (21%), the parallel pattern in 15 (17%), and the cobblestonelike and reticularlike patterns in 4 (5%). A significant association was found between the distribution of multifocal lesions showing a ringlike vs a nonringlike pattern (82% vs 52%; P = .008), whereas a weak association was found between anatomical site and the different patterns (P = .55). The ringlike pattern was frequently combined with multifocality and simultaneous occurrence at the labia majora and the labia minora.

Dermoscopy can be useful for the clinical detection of vulvar melanosis, and the ringlike pattern may represent a new dermoscopic clue for the diagnosis of this lesion.