Spontaneous regression of thymic epithelial tumours.

We herein report the cases of 3 patients with thymic epithelial tumours, including two thymomas and a carcinoma, where the tumours spontaneously regressed in size. The patients were all female ranging in age from 32 to 43 years. During 1 or 2 months without any treatment, the tumours regressed by 25-59% in size. The pleural effusion observed in 2 patients also disappeared during the same period. Pathological examinations revealed areas of necrosis or cystic changes within the two thymomas. Among the patients with thymic epithelial tumours, the existence of this rare disease entity must be recognized.