Extranodal Rosai-Dorfman disease of the head and neck.

Rosai-Dorfman disease is a rare, idiopathic, benign histiocytic proliferation usually seen in younger patients. Massive lymphadenopathy most commonly involves the cervical lymph nodes, with a predominant infiltration of sinusoidal histiocytes. Nearly half of the patients will have extranodal involvement, 75% occurring in sites in the head and neck. Three cases of extranodal Rosai-Dorfman disease of the head and neck involving the nose, paranasal sinuses, and parotid gland are presented. The clinical presentation, histologic characteristics, radiographic findings, and treatment of the disease are discussed. Because of the scarcity of cases, the clinical and histopathologic features of this disease may be overlooked. Familiarity with its relatively frequent clinical manifestations in the head and neck, as well as with the diagnostic histopathology, should preclude confusion with other disease entities.