Results of surgical resection for patients with thymoma according to World Health Organization histology and Masaoka staging

Abstract

Objectives: Thymomas are relatively rare tumors. In this study, we investigated the clinical features of patients who underwent surgical resection for thymoma. Patients and methods: This study clinicopathologically evaluated 54 consecutive patients who underwent a surgical resection of thymoma in our department between 1994 and 2006. Results: A complete resection was performed in 52 patients, while two patients underwent an incomplete resection due to pleural dissemination. Combined resection with adjacent organs was performed for the lung (n=6), pericardium (n=5), and large vessels (brachiocephalic vein in three, superior vena cava in two). The concomitant autoimmune diseases were observed in 20 patients (37%), and they included myasthenia gravis in 17 patients, macroglobulinemia in one, pemphigus vulgaris in one, and stiff person syndrome in one patient. The histologic types of the World Health Organization classification diagnosed as type A in four patients, type AB in 14, type B1 in eight, type B2 in 15, and type B3 in 11. There were 27, 17, eight, and two patients with Masaoka stages I, II, III, and IV, respectively. Four patients died, and the causes of death included recurrence of thymoma in two, gastric carcinoma in one, and respiratory failure due to myasthenia gravis in one patient. The overall survival rate at 10 years was 94.6% in patients with stages I and II disease and 77.1% in patients with stages III and IV disease. Conclusions: Long-term survival can be expected not only for patients at early stages, as well as for patients with stages III and IV disease if surgical resection is completed macroscopically.

Keywords

• autoimmune disease
• mediastinal tumor
• prognosis
• surgical resection
• thymoma