Thymoma--report of 71 cases and a review.

Of the 71 cases of thymoma reviewed, 31 were benign and 40 were malignant. Associated syndromes were common--myasthenia gravis 51% (36/71), red cell aplasia 3%, hypogammaglobulinemia 4%, mucocutaneous candidiasis 1%, and a number of other autoimmune diseases and neoplasms. These were almost equally distributed among benign and malignant tumors. A plain radiograph showing diffuse involvement of the mediastinum always indicates invasive (malignant) thymoma, while a localized pattern usually suggests a benign lesion (25 of 39 cases). Computerized tomography or MRI often gives additional information. An optimistic approach and aggressive radiotherapy are indicated in patients whose only metastatic disease is to one pleural space; prolonged survival is frequent in this group.