[Clinico-pathological characteristics and prognosis of thymoma: an analysis of 159 cases]

To investigate the clinicopathologic features of thymoma and assess prognostic factors.

Data of 159 patients operated for thymoma were collected. A retrospective analysis was performed, through comparison of survival rate computed by the actuarial method and rate of recurrence and metastasis.

(1) The 3-, 5-, and 10-year survival rate was 78.9%, 63.7% and 46.3%, respectively. All patients treated by subtotal thymoma resection with postoperative radiotherapy survived more than 3 years. (2) Patient's age, location and image density of tumor play important role in differential diagnosis. (3) Tumors with epithelial predominance were more frequently seen in late stage than those of other histologic types(P < 0.01). (4) The prognosis of patients whose tumors had incomplete or no capsule was poor as compared to that of stage I tumor (P < 0.05). (5) According to multivariate analysis, the most important prognostic variables included completeness of resection (OR = 2.10) and clinicopathologic stage (OR = 1.73). Myasthenic crisis was the most important factor influencing operative death. Sex, symptoms and histologic classification did not influence prognosis. (6) Recurrence and metastasis occurred in all stages, but more frequent in the later stages of the disease.

Complete resection helps decrease recurrence of thymoma. Prognosis of patients receiving palliative resection of thymoma may be improved by postoperative radiotherapy.