Tumors of the thymus and thymic region: I. Clinicopathological studies on thymomas.

A series of 43 patients with thymoma was reviewed. The patients were classified with respect to some factors of prognostic significance. The tumors were reclassified histologically, and a staging system with three defined stage-groups was applied to the series on the basis of operative findings and histological examination of surgical specimens. Surgical-pathological staging is of high prognostic and therapeutic importance in thymomas. Complete removal of the tumor was possible in the 25 patients with stage I or II disease and in 14 of the 18 patients with stage III tumors. Pleural metastases were observed in half of the patients with stage III disease. Even patients with extensive local spread or pleural metastases were subject to tumor resection. The treatment of choice is radical resection along in stage I; radical extirpation and, if indicated, postoperative radiotherapy in stage II; and radical resection whenever possible, even in cases of pleural spread, in stage III, with postoperative radiotherapy and chemotherapy. Myasthenia gravis is an indication rather than a contraindication to radical treatment of thymoma, although some patients may deterioratte. The importance of total thymectomy is stressed.