Extranodal Rosai-Dorfman Disease presenting as an epibulbar tumor

PURPOSE: To describe a case of an epibulbar tumor as a manifestation of Rosai-Dorfman Disease (RDD) and review the pertinent literature. METHODS: This was an interventional case report and literature review. A 19-year-old African-Brazilian man was referred for evaluation of a 12 x 11-mm subconjunctival mass at the temporal limbus OD. Intraocular pressure was normal, and funduscopy was unremarkable OU. Ultrasound biomicroscopy showed an ill-defined scleral homogeneous lesion at the temporal quadrant, without intraocular invasion. A superficial sclerokeratectomy was performed. RESULTS: Histopathologic evaluation revealed inflammatory aggregates composed of lymphocytes, plasma cells, and histiocytes. The histiocytes appeared pale, and some of them had intact lymphocytes and plasma cells within their cytoplasm. Russell bodies were also found. The histiocytes were positive for CD68 and S-100 and negative for lysozyme and CD1a. Special stains for microorganisms were all negative. Those findings were consistent with the diagnosis of extranodal RDD. Systemic workup failed to reveal lymphadenopathy or extranodal disease elsewhere. At the 14-month follow-up, there were no signs of recurrence. CONCLUSIONS: Although extranodal manifestations are common in RDD and the lack of lymph node involvement is rare, our study supports that whenever there is an epibulbar tumor as a manifestation of RDD, the absence of lymphadenopathy is characteristic. Only 2 of the 9 reported cases presented with lymphadenopathy. The presence of emperipolesis and S-100-positive histiocytes during histopathologic evaluation confirms the diagnosis even in the absence of lymphadenopathy.