Cytology of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease).

Sinus histiocytosis with massive lymphadenopathy (SHML) is a benign, self-limiting condition of unknown etiology, which generally presents as massive bilateral cervical lymphadenopathy. It is important to distinguish SHML from other causes of histiocytosis because of the different treatment modalities. This study was carried out to assess the utility of fine-needle aspiration cytology (FNAC) findings in SHML and to distinguish if from other reactive lymphadenopathies. The lymph nodes in 4 patients (3 male and 1 female) presenting with massive bilateral cervical lymphadenopathy were aspirated. All presented with persistent bilateral cervical lymphadenopathy, polymorphnuclear leukocytosis, and raised erythrocyte sedimentation rate (ESR). Smears showed a reactive lymphoid population consisting of mature lymphocytes, plasma cells, a few polymorphs, and many histiocytes showing emperipolesis. Based on the cytologic and clinical findings, a diagnosis of SHML was made. Histopathology confirmed the diagnosis in all cases. A conclusive diagnosis of SHML can be based on cytology, provided that the cytologic findings are interpreted in the appropriate clinical context. Biopsy can be avoided in these patients. Diagn. Cytopathol. 2000;22:181-185. Copyright 2000 Wiley-Liss, Inc.