Diagnosis of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman Disease) by fine needle aspiration cytology.

Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease) is a rare benign disease of unknown etiology presenting with massive lymphadenopathy. These cases can often be misdiagnosed as lymphoma. Hence, it is important to distinguish Rosai-Dorfman disease from lymphoma and other causes of histiocytosis because of the different treatment modalities. We report here a case of Rosai-Dorfman presenting with massive bilateral cervical lymphadenopathy. We conclude that fine needle aspiration cytology is a useful and reliable tool for the diagnosis of Rosai-Dorfman disease due to which biopsy can be avoided in these patients, thus, reducing inconvenience to patients.