A Case of Localized Amyloidosis of the Brachial Plexus

Localized peripheral neuropathy amyloidosis is a rare disease that mainly occurred in elder people who present with focal neurological symptoms. AL is the main type of amyloid protein. Biopsy is the golden standard for diagnosis. Mass spectrometry and immunohistochemical analysis help to confirm the type of amyloid protein. This paper retrospectively analyzes the clinical and imaging data, auxiliary examinations, histological, and immunohistochemical markers. The patient, a 34-year-old woman, presented with a right neck mass and weakness of the right arm. Brachial plexus magnetic resonance imaging (MRI) showed a tumor-like lesion in the nerve root at C5 and C6 and in upper trunk. Electrophysiological studies revealed damage in the upper trunk of the brachial plexus. Positive staining with Congo red was found in brachial plexus biopsy. Mass spectrometry showed that the type of amyloid protein was AHL(G-λ). The patient underwent nerve graft for treatment. Meanwhile, literature review revealed that the average onset age of localized spinal nerve amyloidosis was 62.4 years old.The radial nerve was the most susceptible, followed by the lumbosacral plexus. Fifty percent of the type of amyloid protein is AL.Until now, no consolidated treatment is available. Here, we summarize the clinical characteristics of localized peripheral neuropathy amyloidosis in order to raise the awareness of the disease.