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.