Dermoscopic features of mucosal melanosis

Melanosis (lentiginosis, labial melanotic macula) is a benign pigmented lesion of mucosa characterized by pigmentation of basal keratinocytes with melanocytic normal or slightly increased in number. Melanosis, particularly when occurring on genitalia, can clinically mimic mucosal melanoma thus creating concern in both the patient and the physician.

In this study dermoscopic features from a series of clinically equivocal (n=11) or clinically typical (n=10) mucosal melanosis were analyzed.

All the women consecutively seen at the Vulva Clinic of the Department of Obstetrics and Gynecology, University of Florence, Italy, from May 1, 2002 to June 30, 2002, were examined.

Three major dermoscopic patterns were identified: (1) a "structureless" pattern, predominantly found in clinically equivocal vulvar melanosis, with a blue hue, associated with the presence of melanophages in the upper dermis, present in the majority of these lesions; (2) a "parallel pattern," often found in clinically typical melanotyc macules of the lips and penis; and (3) a "reticular-like" pattern associated with clinically equivocal melanosis occurring at peculiar sites such as the areola (all the three cases occurred at that site) or, rarely, on the lip.

Dermoscopy can play a role in the noninvasive classification of mucosal melanosis. The risk of misclassification with melanoma is probably dependent on dermoscopy pattern shown by the lesion. Prospective studies including early melanomas are needed to establish diagnostic performance of dermoscopy in pigmented lesions of the mucosa.