2016 Volume 30 Issue 2 Pages 214-217
We report a case of thymoma involving a patient with a history of thymectomy for myasthenia gravis (MG) without thymoma. The patient was an 81-year-old male with a history of MG who initially presented with left ptosis. Crisis occurred and plasmapheresis and steroid pulse therapy were undertaken when he was 64 years old. Extended thymectomy was performed three years later. Pathological analysis showed thymus atrophy, but did not reveal a thymoma, and his symptoms were successfully managed by steroid and immunosuppression therapy. Computed tomography showed a nodule of 17 mm located to the left of his ascending aorta when he was 81 years old. It had been 7 mm in diameter 3 years previously. Acetylcholine receptor (AChR) antibody levels were 91 nmol/L. Video-assisted thoracic surgery was undertaken based on suspected thymoma. Intraoperatively, pericardial invasion was suspected and resection was performed. The histopathological analysis showed invasive thymoma, Masaoka II stage (WHO B3 classification). In this case, we thought that the cause of this recurrence was pleural dissemination from microthymoma. This case also suggests that AChR antibody elevation after extended thymectomy may indicate thymoma.
