[A case report of resected double primary lung cancers in the same one segment].

A 68-year-old man with hypertension was admitted to the Shiga Kenritsu Seijinbyo Center for further examinations, because abnormal opacity in the right upper lung field was accidentally revealed by chest X-ray. Chest CT demonstrated two separate mass shadows, one 31 X 27 mm, the other 10 X 10 mm in size, both of which were located in the posterior segment of right lung. Specimens from transbronchial biopsy of the larger mass was histologically diagnosed as adenocarcinoma. He underwent right upper lobectomy with hilar and mediastinal lymph nodes resections. Postoperative patho-histological study showed the larger mass to be poorly differentiated adenocarcinoma, the smaller one, small cell carcinoma respectively, and no continuity between the two masses. Lymph nodes metastasis were negative. Any malignancy was not detected by brain CT, abdominal CT and any other gastro-intestinal examinations, and he was diagnosed to have double primary lung cancers in the same one segment. In this report, we discussed the diagnosis and treatment of double primary lung cancers, and reviewed the literatures.