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.