The diagnosis of thymoma in myasthenia gravis.
Between 10 and 15 per cent of patients with myasthenia gravis (MG) have a thymoma. We have evaluated the possibility of detecting such tumours on the basis of clinical features, radiological findings and immunological tests in a group of 70 MG patients. The mean age at onset of myasthenic symptoms was 67.6 years in the thymoma group and 33.8 years in the non-thymoma group. Otherwise, the clinical picture was similar. Radiological examination revealed a mediastinal mass in 2 patients. Six of the 70 MG sera contained antibodies to a citric acid (CA) extract of striated muscle. At thymectomy, a thymoma was found in these 6 patients. None of the remaining 64 patients had evidence of a thymoma. Antibodies to AChR were detected in 52 of the 70 MG sera. There was no relation between titres of AChR and CA antibodies. Three out of 5 sera from non-MG patients with a thymoma contained CA antibodies. Apparently, this assay is a valuable technique for the identification of a thymoma at an early stage.
D000368:Aged; D001323:Autoantibodies / Q000032:analysis; D011232:Chemical Precipitation; D005260:Female; D005455:Fluorescent Antibody Technique; D006386:Hemagglutination Tests; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000276:immunology; D009157:Myasthenia Gravis / Q000150:complications*; D011859:Radiography; D011950:Receptors, Cholinergic / Q000276:immunology; D013945:Thymoma / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D013953:Thymus Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging
D001323:Autoantibodies; D011950:Receptors, Cholinergic