Radiation response of Rosai-Dorfman disease presenting with involvement of the orbits

The purpose of this study was to review an interesting case of recurrent orbital sinus histiocytosis. The patient initially failed surgery, chemotherapy, and steroid therapy, only to have a durable response to low-dose radiation therapy of the orbits, lasting 6 and 11 years, respectively. Because there are few documented responses to radiotherapy, we present a case report in conjunction with the clinical, radiographic, and histopathologic information as well as a literature review of similar cases.