Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman Disease): A case report and review of 49 cases with fine needle aspiration cytology.

Rosai-Dorfman disease (RDD), a rare, benign, self-limiting histiocytic proliferative disorder, can be encountered in both nodal and extranodal locations, and fine needle aspiration (FNA), a simple, accurate and economic tool, has been widely used for the diagnosis of superficial and deep-seated lesions. Familiarity with the cytomorphologic features of RDD is important as prognosis and treatment are quite different from other benign or malignant diseases for which it may clinically masquerade. Although large numbers of RDD cases have been reported, review of the literature has revealed 49 reported cases of RDD diagnosed by FNA. Here, we report a case of RDD with nasal and sinus involvement. The patient was seen at our institution, carrying a diagnosis of inflammatory pseudotumor rendered by an outside institution, based on material obtained by nasal and sinus surgical biopsies. Cervical lymph node FNA performed at our institution revealed typical features of RDD. The case, as well as a brief review of the literature and 49 RDD cases with FNA cytology, will be discussed.