[Thymic Carcinoma Operated After Lung Cancer Operation:Report of a Case].

A 70-year-old man presented with the growth of an anterior mediastinal nodule on a follow-up computed tomography (CT) scan after undergoing lung cancer surgery. Positron emission tomography (PET)-CT performed at the time of lung cancer surgery did not recognize any accumulation, but PET-CT performed this time confirmed the accumulation of standardized uptake value( SUV) max 5.57. As a result, we suspected a recurrence of lung cancer and the occurrence of an anterior mediastinal tumor. Therefore, we performed surgery for both resection and diagnostic purposes. Total thymus removal was performed using a subxiphoid approach. The tumor was diagnosed to be thymic squamous cell carcinoma because the immunostaining for CD5 and CD117 was positive. The same type of carcinoma was recognized as a small nodule during the previous lung cancer surgery, and it is considered to represent a synchronous double cancer.