Surgical treatment of thymoma.

OBJECTIVE To describe experience with the surgical treatment of thymoma. DESIGN A retrospective study. SETTING A teaching hospital at the University of Ottawa. PATIENTS Over 25 years, 42 consecutive patients (22 men, 20 women) who had a thymoma requiring operation. INTERVENTIONS Thymectomy. OUTCOME MEASURES Age, sex, association with myasthenia gravis, presence of a paraneoplastic syndrome, extent of surgical resection, tumour size, histologic features of the tumour, clinical staging of the thymoma and short- and long-term outcome after surgery. RESULTS The mean (and standard deviation) age of the patients was 52.8 (12.5) years. Thirteen patients had myasthenia gravis. With respect to tumour staging, 24 patients had stage I, 7 had stage II and 11 had stage III disease. Three patients were lost to follow-up. Radiotherapy was used as an adjunct to surgical treatment in 83% of patients with stages II and III disease. Fifty-one percent of patients available for follow-up survived 175.1 months, and the cumulative 5- and 10-year overall survival rates were 87.3% and 81.4% respectively. Only 1 patient died of metastatic thymoma. Complete or partial remission of myasthenia gravis was seen in 10 (77%) affected patients. Mixed cellular histologic features and a tumour size of less than 115 cm3 were more commonly seen with stage I disease. CONCLUSIONS Thymomas are characterized by slow growth and prolonged survival even in patients with invasive disease as long as the tumour is resected completely and treatment is accompanied by radiotherapy.