title: Malignant thymoma associated with autoimmune diseases: a retrospective study and review of the literature.
abstract: OBJECTIVE
  To determine whether malignant thymoma is associated with high rates of concomitantly occurring autoimmune diseases.
  
  
  METHODS
  Sheba Medical Center computer records from 1966 to 1995 were reviewed to identify patients with malignant thymoma, either type I (invasive thymoma) or type II (thymic carcinoma). All patients who had malignant thymoma and autoimmune phenomena were analyzed. The diagnosis of thymic neoplasm was confirmed by two independent pathologists. The diagnosis of autoimmune diseases was based on both clinical and serological findings.
  
  
  RESULTS
  Six of 22 (27%) cases of malignant thymoma had an autoimmune disease. Five patients had type I malignant thymoma and either myasthenia gravis (four patients) or Graves' disease (one patient). Only one patient had type II malignant thymoma with Sjögren's syndrome. The diagnosis of autoimmune disease preceded the diagnosis of thymic neoplasm in four cases, and was diagnosed simultaneously in two.
  
  
  CONCLUSIONS
  Malignant thymomas are highly associated with autoimmune diseases, as are benign thymomas. To our knowledge, we report the first documented cases of a patient with thymic carcinoma and Sjögren's syndrome, and another with invasive thymoma and Graves' disease.
authors.affiliation: Department of Medicine B, Chaim Sheba Medical Center, Tel-Hashomer, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Levy
authors.forename: A
authors.initials: A
authors.lastname: Afek
authors.forename: Y
authors.initials: Y
authors.lastname: Sherer
authors.forename: Y
authors.initials: Y
authors.lastname: Bar-Dayan
authors.forename: R
authors.initials: R
authors.lastname: Shibi
authors.forename: J
authors.initials: J
authors.lastname: Kopolovic
authors.forename: Y
authors.initials: Y
authors.lastname: Shoenfeld
mesh_terms: D000328:Adult; D000368:Aged; D001327:Autoimmune Diseases / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000150:complications / Q000276:immunology; D012189:Retrospective Studies; D013945:Thymoma / Q000150:complications* / Q000276:immunology*; D013953:Thymus Neoplasms / Q000150:complications* / Q000276:immunology*