T cell lymphocytosis associated with polymyositis, myasthenia gravis and thymoma

Clin Lab Haematol. 2000 Oct;22(5):307-8. doi: 10.1046/j.1365-2257.2000.00312.x.


Peripheral T cell lymphocytosis is a rare finding in association with malignant thymomas. In the majority of previous cases, the tumours have behaved aggressively with symptoms arising from local invasion. We describe a patient with ocular myasthenia gravis who presented with a rapidly progressive polymyositis and neuropathy and who was subsequently found to have a thymic mass and a mild T cell lymphocytosis. The thymoma did not give rise to local symptoms and showed no evidence of progression over a 14-month period of follow-up. The possibility of an underlying thymic tumour should be considered in any patient with chronic T cell lymphocytosis if the circulating cells show mature morphology and there is no molecular evidence of monoclonality.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Humans
  • Lymphocytosis / pathology*
  • Male
  • Myasthenia Gravis / pathology*
  • Polymyositis / pathology*
  • T-Lymphocytes / pathology*
  • Thymoma / pathology*
  • Thymus Neoplasms / pathology*