A case of late-onset polymyositis with autoantibodies to the signal recognition particle

We describe a case of polymyositis (PM) that developed in an 87-year-old woman with autoantibodies to the signal recognition particle. She complained of neither muscular weakness nor myalgia, although muscular weakness was present. Muscle biopsy was not performed because her consent was not obtained. The presence of myositis-specific autoantibodies is helpful in the diagnosis of PM/dermatomyositis lacking the characteristic clinical features or histopathologic confirmation.