Introduction: Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disorder with a predilection for the head and neck. Isolated orbital involvement without systemic clinical features is very uncommon.
Background: Classic histopathologic features include phagocytized but intact lymphocytes within large histiocytes; a conditioned termed emperipolesis. Immunohistochemical stains are strongly positive for S-100 and CD68 but negative for CD1a in most cases. Orbital cases are often amenable to complete surgical resection.
Conclusion: RDD should be considered in the differential diagnosis of a young patient in good health who presents with a marked but benign enlargement of an orbital mass. A review of the literature regarding this disease entity and its orbital manifestations is discussed.