A 64-year-old man presented with left upper limb weakness and dysesthesia for 4 months. Magnetic resonance imaging demonstrated swelling from the 6th-8th left cervical nerve roots to the left brachial plexus. The serum IgG4 level was elevated (762.7 mg/dL). 18F-FDG-PET showed high uptake in the mediastinal lymph nodes, and biopsy revealed infiltration of IgG4-positive plasma cells. We diagnosed IgG4-related neuropathy, and steroid therapy administration improved the symptoms. IgG4-related disease should be considered in the differential diagnosis of peripheral nerve swellings. If biopsy of the disordered nerves is difficult, lymph nodes or other organs should be considered.
Keywords: 18F-fluorodeoxyglucose positron emission tomography; Biopsy; IgG4-related disease; IgG4-related neuropathy.
Copyright © 2022 by The Author(s). Published by S. Karger AG, Basel.