Combined epidermal-connective tissue nevus of proteoglycan (a type of mucinous nevus): a case report and literature review

Abstract

Mucinous nevus is a rare entity with only 11 cases reported previously. It may be divided into two histopathologic types: connective tissue nevus of the proteoglycan (CTNP) and combined epidermal-CTNP. We describe a boy with asymptomatic grouped brown papuloplaques on the lower back since birth. A diagnosis of mucinous nevus of the combined epidermal-CTNP type was made after a biopsy. We vaporized two lesions with carbon dioxide laser, and the wounds healed satisfactorily. We present a literature review indicating a striking preponderance of male patients (M : F = 5 : 1) for mucinous nevus. In half of the cases, mucinous nevus did not appear until childhood, adolescence or early adulthood. The predominantly affected site was the trunk. Half of the cases can be assigned to the CTNP type and the other half to the combined epidermal-CTNP type. We propose that carbon dioxide laser vaporization may be a treatment option for mucinous nevus of the combined epidermal-CTNP type with multiple lesions but not for the CTNP type.