Histiocytose multicentrique avec atteinte cutanée diffuse

Multicentric reticulohistiocytosis is a non Langerhans cell histiocytosis. This rare disease is characterized by cutaneous papules and nodules and a destructive polyarthritis; multisystem involvement may occur. Multiple and diffuse cutaneous reticulohistiocytosis have been more rarely reported. We present a case which was distinctive by the existence of multiple cutaneous plaques.A 65-year-old woman presented cutaneous papules and nodules associated with a destructive arthritis affecting the hands. Histological examination of a cutaneous biopsy associated with immunophenotyping and electronic microscopy permitted us to make the diagnosis of multicentric reticulohistiocytosis. The search for visceral involvement or underlying neoplasia was negative. Rapidly, cutaneous aggravation occurred with multiple and diffuse infiltrated plaques on the back, the face, the ears, the thighs and the forearms. The same histological aspect was found for these lesions. Treatment with corticosteroids and cyclophosphamide was successful.This case report is the first one with diffuse cutaneous lesions of multicentric reticulohistiocytosis with aspect of infiltrated plaques. Diffuse cutaneous lesions in multicentric reticulohistiocytosis have been rarely reported with diffuse papules or nodules pattern. A visceral involvement seems to be more frequent for diffuse cutaneous involvement. In all cases, the association of multicentric reticulohistiocytosis with neoplasia in up to 25 p. 100 is of interest. Treatment of multicentric reticulohistiocytosis consists in corticosteroids at the initial phase associated with alkylants agents or methotrexate.