A Rare Case Report on Choroidal Lymphoma Mistaken for Rhegmatogenous Retinal Detachment: When Inconsistencies Should Raise Suspicions

Aims: The objective of this case presentation is to describe choroidal lymphoma and to promote a structured approach that has enabled us to resolve diagnostic ambiguities. Introduction: Choroidal lymphoma is a subtype of uveal lymphoma and is considered a rare condition. The literature on this subject is limited, which explains why many ophthalmologists are unfamiliar with this pathology. In this case report, we describe the case of a patient presenting with chronic decreased visual acuity in her right eye. The initial diagnosis was rhegmatogenous retinal detachment, which was revised to choroidal lymphoma after further investigations and histopathological confirmation. Case Presentation: We report the case of a 45-year-old woman with chronic decreased visual acuity in her right eye, which had been progressing for three years. She had no history of eye trauma or surgery and was in good general health. After the initial examination, the patient was considered to have a rhegmatogenous retinal detachment of the right eye, and vitreoretinal surgery was scheduled. However, the senior doctor noted some inconsistencies which led to further investigations with a pivotal role for ocular ultrasound, suggesting the possibility of choroidal lymphoma. This diagnosis was then confirmed by histopathological examination, and the systemic workup performed to search for extraocular involvement was negative. Discussion: The diagnosis of choroidal lymphoma is often complex because its symptoms can be similar to those of other eye conditions. Typical manifestations of fundus involvement include solid thickening of the choroid, serous retinal detachment, and anterior and/or posterior epibulbar extension. The diagnosis is confirmed by histopathology, supplemented by immunohistochemistry and flow cytometry. Non-Hodgkin B-cell lymphoma remains the most common type. Monitoring, radiotherapy, chemotherapy, and immunotherapy are the various treatment options for managing choroidal lymphoma, tailored to each individual case. Conclusion: Choroidal lymphoma is a rare condition and little known among ophthalmologists. Consequently, diagnosis is often delayed, as it is sometimes confused with other pathologies, such as rhegmatogenous retinal detachment, as illustrated in our case. A structured approach is essential when dealing with this misleading syndrome.