title: Thymoma detection by mediastinal CT: patient with myasthenia gravis.
abstract: The precise role of computed tomography (CT) in evaluating the mediastinum for thymomas in patients with myasthenia gravis is not defined. The only published CT accuracy assessment reports a false-positive rate of 90%. Mediastinal CT was performed in 23 consecutive unselected patients with myasthenia gravis who underwent thymectomy independent of their neurologic status or diagnostic imaging results. Four patients had discrete thymomas; all were detected by CT. Conventional chest radiography and tomography were positive in three and falsely negative in one. In the remaining 19 patients with a normal or atrophic thymus or microscopic hyperplasia, CT was falsely positive in two; conventional chest radiography and tomography were falsely positive in three. Mediastinal CT is an accurate technique for evaluation of thymoma in patients with myasthenia gravis.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000150:complications*; D013945:Thymoma / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D013953:Thymus Neoplasms / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D014057:Tomography, X-Ray Computed