Lymphadenopathy associated with sinus histiocytosis is known as Rosai Dorfman Disease. Classically it presents as massive bilateral painless cervical lymphadenopathy. We report a unique case of this disease, in which there was involvement of only a single cervical node. The diagnosis was confirmed by documenting the classical cyto-morphological features including emperipolesis. Our case adds a new dimension to the current spectrum of Rosai Dorfman disease and illustrates that an isolated lymphadenopathy can also occur in this disease.