Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease): diagnosis by fine-needle aspiration.

Sinus histiocytosis with massive lymphadenopathy (SHML) is a rare idiopathic proliferative disorder of histiocytes with characteristic morphologic features. We describe a case of SHML occurring in a 14-yr-old black male, in whom the diagnosis was made by fine-needle aspiration of a cervical lymph node. Cytologic features included increased numbers of large histiocytes associated with a polymorphous, cellular background composed of benign lymphocytes, plasma cells, and polymorphonuclear leukocytes. Lymphophagocytosis was a prominent feature. Extranodal involvement of the larynx was documented by surgical biopsy; there was no other extranodal disease. One year after diagnosis, the patient is clinically well, with no residual lymphadenopathy.