An Unusual Case of Extranodal Rosai-Dorfman Disease Manifesting as an Epibulbar Mass.

Purpose: To report an unusual presentation of a 48-year-old man with a salmon-colored epibulbar mass, whose pathology was consistent with extranodal Rosai-Dorfman disease (RDD).

Method: We conducted a retrospective and interventional case report.

Results: A 48-year-old white man presented with progressive left eye irritation, redness, and multiple large subcutaneous nodules on his arms and torso over the past year. He did not have any lymphadenopathy, lymphocytosis, or fever. Visual acuity and intraocular pressures were normal in both eyes. He had mild vertical diplopia on downward gaze. Slit lamp examination revealed a non-tender salmon-colored epibulbar mass of 1.0 × 1.2 cm. Incisional biopsy was performed. Histopathologic evaluation revealed emperipolesis, with positive CD68, positive S100, and negative CD1a staining. These findings were consistent with extranodal RDD. At the 24-month follow-up, there were no signs of recurrence, and his diplopia resolved.

Conclusions: This case of RDD is rare because of the concurrent epibulbar mass with subcutaneous nodules on the torso and arms. Extranodal RDD with epibulbar mass involvement tends to be unilateral, occurring mainly in males, and evenly among people of white and black race. An epibulbar mass of any color should raise concern for systemic lymphoma and RDD. The clinical course for extranodal RDD is typically benign. Excisional biopsy is often done for diagnosis and treatment. Recurrence of the unilateral epibulbar mass after biopsy is rare, but common with bilateral epibulbar masses.