Teaching NeuroImages: diagnostic utility of FDG-PET in neurolymphomatosis.

A 70-year-old woman with a history of non-Hodgkin lymphoma presented with left-sided facial pain. MRI of the face, orbit, and neck was negative (figure). A week later, she developed hypesthesia in a V3 distribution. Repeat MRI was again nondiagnostic but fluorodeoxyglucose (FDG)-PET showed increased uptake along the left V3 branch of the trigeminal nerve, as well as in the parotid gland. Biopsy of the left parotid confirmed recurrent lymphoma. Neurolymphomatosis is a rare manifestation of hematologic disease and diagnosis is often delayed. Our case illustrates the utility of FDGPET in establishing the diagnosis of neurolymphomatosis when suspicion is high but MRI is unrevealing. AUTHOR CONTRIBUTIONS Drs. Toledano, Garza, and Pittock made substantive contributions to the design of the study and drafting of the manuscript. Drs. Siddiqui and Thompson made substantive contributions to the revision of the manuscript.