Surgical management of thymic epithelial tumors: a retrospective review of 204 cases.

BACKGROUND: Thymic epithelial tumors consist of a series of neoplasm that differ morphologically and biologically. Management strategy for these tumors remains controversial.
METHODS: We retrospectively reviewed 204 thymic epithelial tumors surgically treated during the period of 1970 to 1995, and we reexamined the histologic specimens using the current World Health Organization classification.
RESULTS: One hundred eighty patients (88.2%) underwent complete resections, 17 (8.3%) received partial resections, and 7 (3.4%) received biopsies only. The complete resection rate of stages I and II tumors was significantly higher than stages III and IV tumors (98.2% vs 76.6%; p < 0.001). Twenty-four patients (11.8%) experienced 29 events of complications postoperatively, including 11 events of myasthenia gravis crisis. Myasthenia gravis, partial resection or biopsy, and stages III and IV were independent risk factors for postoperative complications. Fifteen patients (7.4%) died during hospital stays, including 6 patients from myasthenia crisis. Partial resection or biopsy and myasthenia gravis were independent risk factors for postoperative mortality. There were significantly more stage I and stage II cases in histologic types A, AB, and B1 tumors than in B2, B3, and C tumors (87.6% vs 26.4%; p < 0.001), and their complete resection rate was significantly higher than the latter group (98.9% vs 78.3%; p < 0.001). The 5-year and 10-year survival rates were 63.2% and 50.4%, respectively. Masaoka stages III and IV, histologic types B2, B3, and C, and incomplete resection were independent risk factors for poor prognosis.
CONCLUSIONS: Complete resection remains the hope of cure for thymic epithelial tumors. The treatment strategy should be based on the current World Health Organization histologic classification and the Masaoka staging system.