Hamartome dendrocytaire dermique à type de médaillon : à propos d'un cas

Medaillon-like dermal dendrocyte hamartomas are rare congenital cutaneous lesions. They are present at birth as asymptomatic, benign, round, erythematous, well-circumscribed, atrophic patches. Typically, they have characteristic pliable, wrinkled surface; subtle telangiectases may also be appreciated. They are localized on the upper trunk or the neck. They may be misdiagnosed as atrophoderma, cutis aplasia, or anetoderma. Characteristic histologic findings include epidermal atrophy and the presence of CD34-positive spindle cell proliferation in the dermis. Little is known about the pathophysiology of medaillon-like dermal dendrocyte hamartomas. The main diagnosis pitfall is atrophic congenital dermatofibrosarcoma protuberance due to clinical and histological similarities. We emphasize that molecular studies to eliminate the t(17;22)(q22;q13) translocation of dermatofibrosarcomas may provide determinant elements for diagnosis in order to avoid unnecessary mutilating surgery. We present a case of medaillon-like dermal dendrocyte hamartoma with a local recurrence.