Choroidal Involvement in Rosai-Dorfman Disease Successfully Treated with Cobimetinib

Rosai- Dorfman disease (RDD) is a rare systemic pseudo-lymphomatous disorder with unknown etiology. No guidelines exist regarding its management and treatment when the disease is progressing. Choroidal involvement in RDD has rarely been reported and has often been misdiagnosed. We describe a case of a 64-year-old male diagnosed with RDD by means of choroidal biopsy, successfully treated with a MEK inhibitor, namely Cobimetinib, and its follow-up over 5 years, with good final anatomical and functional results. This is the first reported case of RDD diagnosed with an intraocular biopsy performed on a non-enucleated globe, thus preserving the integrity and function of the eye. This case emphasizes the need for a choroidal biopsy when the diagnosis is not straightforward and the starting of targeted therapy to retain a good visual function.