PRIMARY CHOROIDAL MALIGNANT LYMPHOMA:REPORT OF A CASE AND REVIEW OF LITERATURE

Non-Hodgkin lymphoma (NHL) is one of the masquerade syndromes of malignant melanoma that can occur with two main patterns of presentations in the eye: metastatic involvement of uveal tract, and primary involvement of retina. We report ophthalmic, imaging and histopathological findings in the first case diagnosed as primary choroidal NHL without central nervous system or systemic involvement. A 37-year-old woman presented with the complaint of severe visual loss in her right eye. Significant ocular finding included light perception of vision (LP), 2+ APD, 2+ cells in vitreous and intraocular pressure of 46 mmHg. Fundoscopic examination revealed exudative retinal detachment. Ocular echography showed choroidal thickening in addition to retinal detachment. MRI showed semilunar shape lesion in the posterior right globe suggesting choroidal melanoma. Systemic work-up could not reveal any underlying cause. The patient underwent enucleation with clinical suggestion of choroidal melanoma. Result of histological examination showed NHL (diffuse large Bcell type) of choroid. Immunohistochemical staining showed negative staining for HMB-45 and CD3, positive staining for LCA, and CD20. Multiple periodic lumbar puncture, bone marrow biopsies and MRI were unremarkable. No recurrence of tumor in systemic work-up was noted during the 36-months follow-up. Primary choroidal NHL is one of the causes of generalized thickening of choroid and should be considered in differential diagnosis of malignant melanoma. It is recommended to perform fine needle biopsy before performing surgery in any patient who has had an atypical malignant melanoma. This is, so far as we know, the first case diagnosed as primary choroidal NHL.