Homonymous Hemianopia: A Rare Presentation of Secondary Central Nervous System Neurolymphomatosis.

Neurolymphomatosis is an atypical complication of non-Hodgkin lymphoma and leukaemia involving infiltration of neurotropic neoplastic cells in the central or peripheral nervous system. A 28-year-old Malay lady with background diffuse large B-cell lymphoma stage IV presented with left homonymous hemianopia associated with cognitive function deterioration. Her best corrected visual acuity was 6/9 in both eyes. Magnetic resonance imaging (MRI) of the brain showed a lesion suggestive of secondary lymphomatous infiltration of the splenium of corpus callosum. The patient underwent chemotherapy, after which repeated MRI showed a reduction in the lesion size. Homonymous hemianopia is a rare presentation of secondary central nervous system neurolymphomatosis. A comprehensive history, physical examination, and radiological imaging are essential to establish the diagnosis in patients presenting with visual field defects.