Fine needle aspiration (FNA) cytology of Rosai Dorfman disease.

Rosai Dorfman disease (sinus histiocytosis with massive lymphadenopathy (SHML)) is a benign self-limiting disorder that commonly involves the lymph nodes. We reviewed eight cases of this entity aiming to document the cytomorphological features. Of the eight cases, a preoperative diagnosis was suggested in seven cases. Pertinent features included: numerous large histiocytes with prominent emperipolesis (documented by a halo around the cell), fine vacuoles in the cytoplasm and lymphocytes and plasma cells in the background. In some cases the histiocytes showed atypia. In one biopsy-proven case a diagnosis of Hodgkin's was suggested, emphasizing the pitfalls associated with the FNA diagnosis of this lesion.