A surgical case of primary lung cancer with peripheral intrapulmonary lymph node metastasis.

We report on a case of a patient with lung adenocarcinoma and peripheral intrapulmonary lymph node (IPLN) metastasis who was misdiagnosed as having intrapulmonary metastasis. A subpleural nodular shadow visualized by radiography was diagnosed as an intrapulmonary metastasis originating from primary lung cancer. Preoperative evaluation indicated that this case was a clinical T4N1 lung adenocarcinoma with metastasis in the same lobe. However, postoperative evaluation showed that it was a peripheral IPLN metastasis, and this was actually a case of pathologic T2N1 adenocarcinoma. It may have been possible to treat this case non-surgically with the possibility of radical cure. This case suggests that a nodule is present in the same lobe with lung cancer, and it must be borne in mind that IPLN metastasis may be misdiagnosed as intrapulmonary metastasis.