A case of peripheral nerve microvasculitis associated with multiple myeloma and bortezomib treatment

Introduction: Bortezomib-induced peripheral neuropathy typically presents as a painful, length-dependent sensory predominant neuropathy. Methods: A case report, including nerve pathology, is presented of a man with multiple myeloma who developed a severe motor predominant polyradiculoneuropathy in the setting of bortezomib treatment. We also review the Mayo Clinic Hematology Dysproteinemia database for patients treated with bortezomib. Results: A 53-year-old man with Stage III multiple myeloma developed a severe motor predominant polyradiculoneuropathy following bortezomib treatment with electrophysiological features of multiple conduction blocks and pathological evidence of peripheral nerve microvasculitis. Our institutional experience is that 36.5% of dysproteinemia patients treated with bortezomib develop treatment-emergent peripheral neuropathy, and the most common pattern is a painful sensory predominant peripheral neuropathy. Conclusions: A motor predominant polyradiculoneuropathy is a rare presentation of bortezomib-associated peripheral neuropathy in multiple myeloma patients which may progress despite treatment withdrawal and may be due to microvasculitis.