Paraneoplastic myopathies

Handb Clin Neurol. 2024:200:327-332. doi: 10.1016/B978-0-12-823912-4.00022-0.

Abstract

This chapter reviews the association between cancer and the idiopathic inflammatory myopathies (IIM), which includes dermatomyositis (DM), antisynthetase syndrome (ASyS), immune-mediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM). Accumulating evidence shows that the risk of a coexisting malignancy is high in patients with DM, especially among those with anti-Tif1γ autoantibodies. Patients with IMNM and no defined autoantibodies also have an increased risk of malignancy. Recent evidence demonstrates that many IBM patients have increased numbers of circulating CD57+ CD8+ T cells, consistent with a diagnosis of large granular lymphocytic leukemia. In contrast, IMNM patients with anti-SRP or anti-HMGCR autoantibodies as well as patients with ASyS syndrome do not have a definitively increased risk of cancer. Patients who have a cancer treated with one of the immune checkpoint inhibitors can develop myositis (ICI-myositis), sometimes along with myasthenia gravis and/or myocarditis.

Keywords: Antisynthetase syndrome; Autoantibody; Cancer; Dermatomyositis; Idiopathic inflammatory myopathy; Immune checkpoint inhibitor; Immune-mediated necrotizing myopathy; Inclusion body myositis; Myasthenia gravis; Myocarditis; Myositis.

Publication types

  • Review

MeSH terms

  • Autoantibodies
  • Humans
  • Muscle, Skeletal / pathology
  • Myasthenia Gravis* / pathology
  • Myositis* / complications
  • Myositis* / diagnosis
  • Myositis, Inclusion Body* / diagnosis
  • Myositis, Inclusion Body* / pathology

Substances

  • Autoantibodies

Supplementary concepts

  • Antisynthetase syndrome