Thymomas: Clinicopathologic features, therapy, and prognosis

Fifty-four patients with thymoma were seen at Memorial Hospital from 1928 to 1972. There were 18 benign and 36 malignant thymomas. Benign tumors were completely encapsulated. Malignant tumors were non-encapsulated or incompletely encapsulated and invasive. All patients with benign thymoma were treated by resection alone. None had recurrent disease or died with tumor for periods ranging from 5 to 17 years after resection. Patients with malignant thymoma treated by resection alone had recurrent tumor within 5 years and subsequently died of their disease. All malignant thymoma patients who were alive free of disease for 5 or more years had radiation therapy and resection. Clinicopathologic features indicating a poor prognosis were: a non-encapsulated tumor of a predominantly epithelial cell type, superior vena caval syndrome, malignant pleural effusion, supraclavicular lymph node involvement, dysphagia, hoarseness, myasthenia gravis, erythroid hypoplasia, and hypogammaglobulinemia.