A 72-year-old woman presented with gradually-worsening myalgia and muscle weakness of the proximal lower limbs as well as elevated serum creatine kinase level. Based on a clinicoseropathological examination including a muscle biopsy, she was diagnosed with anti-signal recognition particle (SRP) myopathy. Although the myopathy relapsed two times in two years under oral prednisolone and intravenous immunoglobulin therapy, the myopathy remained in remission for more than three years after resection of gastric cancer. Although the anti-SRP myopathy is not considered to be cancer-associated in general, we should note that some cases of anti-SRP myopathy may be ameliorated with appropriate cancer treatment.
Keywords: MRI; anti-glutamic acid decarboxylase antibody; anti-signal recognition particle myopathy; gastric cancer; intravenous immunoglobulin, muscle biopsy.