The correlation of the World Health Organization histologic classification of thymic epithelial tumors and its prognosis: a clinicopathologic study of 108 patients from China.

This study retrospectively reviewed the clinicopathological features of thymic epithelial tumors in 108 patients, and evaluated World Health Organization (WHO) histologic classification of thymic tumors. Other prognostic factors, including age, gender, clinical stage, and completeness of tumor resection were also analyzed. Seven type A tumors, 19 type AB, 23 type B1, 19 type B2, 27 type B3, and 13 thymic carcinomas were studied. The 5-year and 10-year survival rates were 100% after resection of tumor types A and AB; 93% and 81% for B1; 83% and 70% for B2; and 43% and 33% for B3. The overall 5-year and 10-year survival rates were 72.0% and 63.0%, respectively. Tumor classification was highly significant in predicting survival (P .001) and also reflected the clinical behavior of tumors. The Masaoka stage was the most important independent prognostic index in thymomas. The WHO histologic subtype and completeness of resection were also important prognostic factors.