Thymoma-associated autoimmune encephalitis with myasthenia gravis: Case series and literature review

CNS Neurosci Ther. 2024 Feb;30(2):e14568. doi: 10.1111/cns.14568.

Abstract

Objectives: This comprehensive review aimed to compile cases of patients with thymoma diagnosed with both autoimmune encephalitis (AE) and myasthenia gravis (MG), and describe their clinical characteristics.

Methods: Clinical records of 3 AE patients in the first affiliated hospital of Sun Yat-sen University were reviewed. All of them were diagnosed with AE between 1 November 2021 and 1 March 2022, and clinical evidence about thymoma and MG was found. All published case reports were searched for comprehensive literature from January 1990 to June 2022.

Results: A total of 18 cases diagnosed with thymoma-associated autoimmune encephalitis (TAAE) and thymoma-associated myasthenia gravis (TAMG) were included in this complication, wherein 3 cases were in the first affiliated hospital of Sun Yat-sen University and the other 15 were published case reports. 5/18 patients had alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antibody (AMPAR-Ab) in their serum and cerebrospinal fluid (CSF). All of them had positive anti-acetylcholine receptor antibody (AChR-Ab). And 12/18 patients showed a positive response to thymectomy and immunotherapy. Besides, thymoma recurrences were detected because of AE onset. And the shortest interval between operation and AE onset was 2 years in patients with thymoma recurrence.

Conclusions: There was no significant difference in the clinical manifestations between these patients and others with only TAMG or TAAE. TAAE was commonly associated with AMPAR2-Ab. Significantly, AE more commonly heralded thymoma recurrences than MG onset. And the intervals of thymectomy and MG or AE onset had different meanings for thymoma recurrence and prognoses of patients.

Keywords: autoimmune encephalitis; myasthenia gravis; thymectomy; thymoma.

Publication types

  • Review

MeSH terms

  • Encephalitis* / complications
  • Encephalitis* / therapy
  • Hashimoto Disease*
  • Humans
  • Myasthenia Gravis* / complications
  • Myasthenia Gravis* / therapy
  • Thymoma* / complications
  • Thymoma* / diagnosis
  • Thymoma* / surgery
  • Thymus Neoplasms* / complications
  • Thymus Neoplasms* / diagnosis
  • Thymus Neoplasms* / surgery

Supplementary concepts

  • Hashimoto's encephalitis