Prognostic factors of thymomas.

Thymomas are uncommon tumours. This study analyses the prognostic value of certain clinical variables and of two different histological classifications. Thirty cases were analysed; 24 were women and six men, with a mean age of 50 years (range 22-69). The pre-operative study included: clinical data (Masaoka's and Osserman's clinical classification); chest radiography; and computed axial tomography. Surgery was divided into three categories: total tumour resection, partial resection and biopsy alone. For the pathological study we followed Salyer-Eggleston and Marino-Müller classifications. Follow-up averaged 5.5 years (range: 2-11). As a statistical method we used Kaplan-Meier's survival curves and Cox's regression model. Eleven of the patients had associated myasthenia gravis, this being the most common clinical type. Age, sex, association with myasthenia gravis, surgical technique and Salyer-Eggleston's classification showed no prognostic value; conversely, clinical staging and Marino-Müller's classification had a high prognostic value. The first treatment that should be considered is surgery, with an attempt to perform total tumour resection. Myasthenia gravis did not modify the prognosis of the disease. The factors of greatest prognostic significance were clinical staging and Marino-Müller's histological classification.