Extranodal Rosai-Dorfman disease of the kidney

Ann Saudi Med 29(1) January-February 2009 www.saudiannals.net 55 Lampert and Lennert in 1961 were the first to describe what is now known as Rosai-Dorfman disease (RDD). Subsequently in 1969, Rosai and Dorfman described 4 cases of a disease they called sinus histocytosis with massive lymphadenopathy (better known as RDD).1 In 1972 they analyzed 30 additional cases, establishing RDD2 as a clinicopathologic entity. RDD generally manifests in children or young adults with massive cervical lymphadenopathy, fever, leukocytosis, an increased erythrocyte sedimentation rate and hypergammaglobulinemia. Other lymphatic groups such as mediastinal, axillary and inguinal lymph nodes can also be affected.3 In about 25% to 40% of cases, extranodal sites are also affected. Extranodal RDD lesions may occur with or without lymphadenopathy and may be solitary or multiple.4 The concomitant involvement of one or more sites in the same individual is observed in up to 44.7% of cases. Extranodal involvement is often responsible for the most important clinical manifestations of the disease.5 Despite its alarming appearance, RDD is considered a benign condition in the majority of cases because of its self-limited course. We report a rare case in which the patient presented with initial involvement of the left kidney in the absence of nodal involvement.