Abstract
PURPOSE: To describe the clinicopathological characteristics of ophthalmic Rosai-Dorfman disease (RDD). METHODS: A 15-year single-center retrospective case series on ophthalmic RDD. RESULTS: Thirteen cases of ophthalmic RDD were identified, including eight males and five females, with a mean age of 49.2 years. The most common presenting signs were eye redness (76.9%) and proptosis (61.5%). The orbit was the most frequently involved site (84.6%). Epibulbar masses occurred in 53.8% of cases, and one case had a concurrent uveal lesion. Eyelid involvement was noted in 46.2% (six cases). Compressive optic neuropathy was documented in 23.1% (three patients). Bone erosion was observed in 53.8% (seven patients). Systemic involvement was present in 69.2% (9 patients), and lymphadenopathy was detected in 15.4% (two patients). Paranasal sinus infiltration occurred in 38.5% (five patients). Other systemic associations included skin and retroperitoneum/kidney (both 15.4%), cerebrum (7.7%), and cardiovascular system (7.7%). Histopathology revealed large S-100-positive histiocytes with emperipolesis in an inflammatory and fibrotic background in all cases. All were BRAF V600E negative, except one with a coexisting Erdheim-Chester-like lesion, suggesting mixed histiocytosis due to overlapping phenotypes with Erdheim-Chester disease (ECD). Increased IgG4-positive plasma cells were seen in 38.5% (five cases). CONCLUSIONS: Ophthalmic RDD most frequently presents with orbital and epibulbar masses and rarely involves the uvea. Increased IgG4-positive plasma cells in some RDD cases necessitate careful differentiation from IgG4-related disease. In rare conditions, overlapping clinicopathological phenotypes with ECD and BRAF V600E mutation suggest a diagnosis of mixed RDD/ECD.