Full Text of PDF (396k)
Article in Japanese
Abstract
Case Report
A case of lung cancer with myasthenia gravis-like myositis induced by pembrolizumab
Terukazu Takahashia Shigeto Hontsua Masato Tasakia Takafusa Andob Kazuma Sugieb Shigeo Muroa
aDepartment of Respiratory Medicine, Nara Medical University
bDepartment of Neurology, Nara Medical University
ABSTRACT
A 71-year-old man receiving chemotherapy for non-small cell lung cancer noticed diplopia, left ptosis, and bilateral lower leg pain three weeks after initial treatment with the immune checkpoint inhibitor pembrolizumab. Creatine kinase levels had increased to 6,001 U/L and magnetic resonance imaging of the thigh revealed inflammation of the right vastus medialis. He tested negative for autoantibodies related to inflammatory myopathy. We diagnosed him with pembrolizumab-related myasthenia gravis-like myositis based on clinical symptoms, elevation of muscle enzymes, and the areas of muscle inflammation revealed on magnetic resonance imaging. Treatment with prednisolone rapidly ameliorated serum creatine kinase levels. We administered intravenous immunoglobulin, steroid therapy, and plasma exchange therapy. His symptoms gradually improved and he was discharged on the 85th day after admission.
KEYWORDS
Pembrolizumab Immune-related adverse event (irAE) Myositis
Received 7 Mar 2023 ／ Accepted 12 May 2023
AJRS, 12(4): 220-224, 2023
Copyright © The Japanese Respiratory Society All Rights Reserved.