Thymectomy for myasthenia gravis: A pathological analysis

Abstract

Background: Myasthenia gravis (MG) is a prototypic T-cell-dependent antibody-mediated autoimmune disease that leads to ocular or generalized muscular weakness. The disease is most commonly caused by antibodies to the acetylcholine receptors, often with underlying thymic pathology.

Aims: This study is aimed at analyzing the pathological spectrum of the excised thymuses in patients with myasthenia.

Materials and methods: This was a retrospective 10-year study of 68 thymectomy specimens performed as a part of the treatment of patients with MG.

Statistical analysis: Nil.

Results: There were 47 males and 21 females (male to female ratio of 2.2:1) with a mean age of 41 years. Only three patients presented with ocular myasthenia. The thymus was normal in 9 patients (13.2%) and atrophic in 17 patients (25%). Follicular hyperplasia and thymomas were seen in 6 and 36 patients, respectively.

Conclusion: The thymectomies performed in patients of MG had a fairly variable spectrum on histology; the thymic tumors were predominantly of the cortical phenotype.

Keywords: Atrophy; follicular hyperplasia; myasthenia gravis; thymectomy; thymoma; thymus.