[Rosai-Dorfman disease: Sinusal histiocytosis with massive lymphadenopathy].

Rosai-Dorfman sinusal histiocytosis is a benign histiocytic disorder presenting as large lymphadenopathies, mostly in the cervical area. Visceral involvement is not unusual. The diagnosis is based on histologic findings, showing intrasinusoidal histiocytic infiltration with pathognomonic emperipolesis features. Histiocytes display a normal activated phenotype. It probably represents a heterogeneous group of diseases with some common histopathologic findings. An association with immunologic abnormalities or auto-immune diseases, mostly auto-immunes cytopenias is possible. This is a criterion of poor prognosis. The evolution can sometimes be spontaneously favorable. Nonetheless, there is a risk of compression, due to the huge volume of tumoral masses, especially in case of orbital or epidural involvement. Therapeutic abstention is usually justified. Treatments are discussed in threatening forms, evolving forms or in case of poor prognosis factors. Treatment, when indicated, is not codified. Surgery, corticosteroids, immunosuppressive agents and/or alpha interferon can be used.