[A case of neurolymphomatosis diagnosed with FDG-PET]

A 38-year-old man with non-Hodgkin's lymphoma presented with hypesthesia and muscle weakness in the left upper limb. A lack of F-waves in left median and ulnar nerve conduction studies suggested a lesion at the proximal segments of the peripheral nerves, such as the left brachial plexus or nerve roots. Cervical magnetic resonance imaging revealed no lesions compressing nerve roots or peripheral nerves. Small and obscure uptake on the left side of the cervical nerve roots on 67Ga-scintigraphy was indistinguishable from artifact. Positron emission tomography-computed tomography (PET/CT) revealed a region of high glucose uptake in a left cervical intervertebral foramen, leading to a diagnosis of neurolymphomatosis. Neurological symptoms improved following additional chemotherapy, and the high glucose-uptake lesion disappeared. FDG-PET/CT is useful for rapid and non-invasive evaluation of neurolymphomatosis.