[Synchronous multiple primary lung and colon cancers]

We report a rare surgical case of synchronous multiple primary lung cancers with synchronous multiple colon cancers. A 74-year-old woman was incidentally pointed out abnormal chest shadows. Chest computed tomography revealed 2 nodules in the right upper and middle lobe. Transbronchilal lung biopsy (TBLB) was done, and the tumor in the middle lobe was diagnosed as adenocarcinoma. In addition, positron emission tomography pointed out colon cancer. Colon fiber revealed multiple colon polyps and colon cancers. Immunostaining with thyroid transcription factor (TTF)-1 and Napsin-A for TBLB specimen was done to distinguish their association. With the diagnosis as primary lung cancer, we performed right upper and middle lobectomy with lymph node dissection. These tumors were pathologically diagnosed as synchronous multiple primary lung cancers with adenocarcinoma and squamous cell carcinoma. Several months later, colon regions were resected through colonoscopic endometric mucosal resection and left hemicolectomy.