[Experience with invasive thymoma presenting pleural dissemination].

A 61-year-old man was admitted to Showa University Hospital because of a myasthenia gravis. Chest computed tomography revealed a mediastinal invasive tumor. During surgery, invasion to the pericardium and dissemination on the left visceral pleura and the left diaphragm were observed. Extended thymo-thymectomy and partial resection of the pericardium, left lung, and diaphragm were performed. Incomplete resection was achieved because of the dissemination on the diaphragm. Chemotherapy using ADOC and radiotherapy for mediastinum and left diaphragm were done. Four years after surgery, neither recurrence of the tumor nor myasthenia gravis was observed.