Linear atrophoderma of Moulin on the neck.

Background: Linear atrophoderma is a rare disease, first described by Moulin in 1992 in 5 patients. It is an acquired unilateral hyperpigmented, depressed band-like areas following the lines of Blaschko. It affects children or adolescents of both genders involving the trunk or the limbs. It is considered to be a rare cutaneous form of mosaicism.

Main Observation: A 39-year-old woman with a 22 years history of unilateral slightly depressed hyperpigmented lesion on her neck was admitted to us. The skin texture was normal and there were no signs of induration or sclerosis. The histopathological examination revealed a normal epidermis outlined by a hyperpigmented basal layer. In the papillary dermis proliferation of superficial vessels with mild lymphocytic infiltrate and melanin-laden macrophages were present. The collagen fibres and elastic fibres were normal. The clinical and histopathological features confirmed the diagnosis of linear atrophoderma of moulin. We discussed the case according to the other cases reported in the literature.

Conclusions: Approximately 28 cases of linear atrophoderma have been reported in literature. The present case has the charecteristic clinical and histopathological features of linear atrophoderma as defined by Moulin, but the localization of the lesion is unusual.