Spontaneous regression of thymona: Report of two cases

Abstract

We herein report the cases of 2 patients whose thymomas spontaneously regressed. The first patient was a 71-year-old woman who was admitted to a nearby hospital due to the sudden onset of chest pain. Chest computed tomography (CT) showed an anterior mediastinal mass of 8×10 cm with pleural and pericardial effusion. She was scheduled to undergo tumor extirpation or thymectomy at our hospital. A chest CT examination carried out just before the surgery revealed tumor regression to 6.5×7.5 cm and the disappearance of the pleural and pericardial effusion a month after the first presentation. The second patient was a 59-year-old woman who was admitted to a nearby hospital due to a cough. Chest CT showed an anterior mediastinal mass of 6×2 cm. She was scheduled to undergo tumor extirpation or thymectomy at our hospital. A chest CT examination carried out just before the surgery revealed tumor regression to 5×1 cm 6 months after the first presentation. The pathological diagnosis of each case was a thymoma, and microscopic findings showed a necrotic area in the central part of the resected tumor.