Rosai-Dorfman disease mimicking cavernous hemangioma: a case report.

A 31-year-old female presented to the clinic with a 2 year history of proptosis of the right eye. She was diagnosed with cavernous hemangioma during her initial ophthalmologic consult and was advised monitoring. However, after a considerable increase in proptosis, she underwent an excision biopsy of the right orbital mass. A diagnosis of Rosai Dorfman disease was made after the histopathology report revealed a fibrosclerotic tissue with histiocytic proliferation showing emperipolesis that is mixed with numerous small lymphocytes and plasma cells. Rosai Dorfman disease is a rare disease presenting with lymphadenopathy and sinus histiocytosis. Orbital involvement can be the principal manifestation with proptosis as the most common presentation. Resection of the orbital lesion helped in the resolution of the mild ophthalmic symptoms but since the disease has other systemic associations, a complete systemic workup should be done to monitor recurrence.