florbetapir-f-18 and Amyloid-Neuropathies

Multiple mononeuropathy is a rare presentation of primary (AL) amyloidosis and nerve biopsy is usually needed for diagnosis. Conventional imaging is useful to identify proximal nerve involvement but may be inadequate. We report a patient with multiple mononeuropathy whose presentation was suggestive of AL amyloid neuropathy and in whom repeated tissue biopsies were negative for amyloid (including two sensory nerves and one muscle).

Topics: Amyloid Neuropathies; Amyloidosis; Aniline Compounds; Biopsy; Ethylene Glycols; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Mononeuropathies; Neurosurgical Procedures; Positron-Emission Tomography

We present a case of both F-FDG and F-florbetapir uptake in a biopsy-confirmed immunoglobulin light chain (AL) amyloidosis involving the peripheral nerves. AL amyloidosis is the most common cause of acquired amyloid polyneuropathy, manifesting with both sensorimotor and autonomic neuronal dysfunction. Given the overlapping MRI and FDG PET/CT appearances of several different causes of peripheral neuropathy, F-florbetapir PET/CT provides another potential tool in the imaging algorithm of these patients and may guide targeted fascicular biopsy for pathologic confirmation.

Topics: Amyloid Neuropathies; Amyloidosis; Aniline Compounds; Ethylene Glycols; Fluorodeoxyglucose F18; Humans; Immunoglobulin Light-chain Amyloidosis; Male; Middle Aged; Multimodal Imaging; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, X-Ray Computed