[A case of synchronous primary lung cancer with hamartoma]

We present a case of a synchronous primary lung cancer adjacent to a hamartoma. In a 48-year-old man, a nodular shadow was found in the right middle lung field in 1990, and had grown slowly for 10 years. Another mass shadow was detected in the right upper lung field in 2000. The patient was admitted to our hospital for further examination of these abnormal shadows. Bronchoscopic examination revealed, in the right upper lobe, a poorly differentiated adenocarcinoma of clinical stage IIIB. Neoadjuvant chemotherapy followed by pneumonectomy was performed. The microscopic findings for the tumor resected from the right S2 showed poorly differentiated adenocarcinoma and those for the other, in the right S3, showed chondromatous hamartoma. Some 50 reports of lung cancer in parents with a chondromatous hamartoma have appeared in the literature. Most of these cases have some common features as follows: 1) men past middle age, 2) adenocarcinoma, and 3) lung cancer and chondromatous hamartoma present in the same lobe. The present case had all of these features, and may assist in the understanding of the process of development of lung cancer adjacent to a hamartoma.