Ocular manifestation of primary nervous system lymphoma: what can be expected from imaging?

Primary ocular lymphoma, which affects the posterior parts of the eye, is an ocular manifestation of primary central nervous system lymphoma (PCNSL). It used to be the ocular disease with the shortest time of survival, even worse than ocular melanoma. Death ensues by CNS dissemination. Unfortunately, ocular lymphoma may be the initial manifestation of PCNSL and diagnosis is frequently difficult, even if vitreal biopsy is performed. Therefore, it should be determined whether cross sectional imaging may be helpful in detection and differential diagnosis of ocular lymphoma. MRI of seven patients (female = 6, male = 1, median age 62 years) with biopsy proven ocular lymphoma were retrieved from the files of our hospital and of a multicenter PCNSL study. In four patients, ocular lymphoma was the first manifestation of PCNSL, in three a cerebral lesion had occurred in the first place. Progression to cerebral lymphoma was seen in three of the four patients with initial eye manifestation. Imaging was performed using a dedicated thin section protocol in four patients. An intraocular abnormality was found in four cases, always in T1-weighted images after contrast injection. Differential diagnosis from uveitis or ocular melanoma was not possible by imaging alone. The examination was falsely negative in the remaining three patients.Hence, imaging has a low sensitivity for ocular lymphoma and does not facilitate differential diagnosis against uveitis or ocular melanoma.