A Rare Case of Primary Ventricular Lymphoma Presented on FDG PET/CT.

Primary ventricular lymphoma is a rare form of non-Hodgkin lymphoma confined to the central nervous system. A 51-year-old woman presented with a 4-month history of unsteady gait and progressive decline in memory. An outside brain MRI showed multiple space-occupying lesions in the ventricles, which suggested malignancy. Staging with FDG PET/CT demonstrated not only hypermetabolic masses in the lateral, third, and fourth ventricles but also a hypermetabolic lesion in the spinal cord. A biopsy of the right lateral ventricle tumor confirmed diffuse large B-cell lymphoma.