A rare cause of massive lymphadenopathy.

Rosai Dorfman Disease is a rare disease presenting mainly as painless enlargement of cervical lymph nodes. It is a benign disorder showing unique histological features characterized by reactive proliferation of sinus histiocytes. In 40% of cases, extranodal sites may be involved. The condition has to be differentiated from certain types of B cell lymphoma showing similar features. We report here a 17 year old male presenting with nodal and extranodal involvement of Rosai Dorfman Disease.