F-18 2-fluoro-2-deoxy-glucose positron emission tomography/computed tomography for the detection of radicular and peripheral neurolymphomatosis: correlation with magnetic resonance imaging and ultrasound.

Neurolymphomatosis is an uncommon extranodal manifestation of non-Hodgkin lymphoma. It may mimic a broad variety of neurologic conditions which renders clinical diagnosis challenging. As blind nerve biopsy is invasive and may be false negative, surrogate criteria for the diagnosis of neurolymphomatosis have been proposed based on magnetic resonance imaging/computed tomography findings. However, these morphologic modalities may suffer from limited sensitivity. Recently, a few reports have been published that discuss a possible advantage of F-18 2-fluoro-2-deoxy-glucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in these patients.We report the case of a 41-year-old man who presented with progressive tetraparesis and dysaesthesia, in which F-18 FDG PET/CT aided to the diagnosis of neurolymphomatosis due to a large B-cell lymphoma. The patient received chemotherapy (R-CHOP) and the neurologic symptoms were clearly regressive. Three months after the end of systemic chemotherapy the patient presented again with progressive neurologic symptoms. A second PET/CT was performed and demonstrated disease recurrence in the right testis as well as widespread neurolymphomatosis. Additional ultrasound and magnetic resonance imaging examinations were performed and confirmed infiltration of the left brachial plexus, the right femoral, and the right sciatic nerve.We present this case to support the hypothesis that F-18 FDG PET/CT is a valuable imaging modality in patients with suspected neurolymphomatosis. It allows one to accurately determine the extent of the disease in a single whole-body examination.