[A Case of Simultaneous Multiple Metastatic Lung Tumors with Different Primary Organs]

A 74-year-old man was found to have 2 nodules with an enlarging tendency in the left lung 2 years 4 months after undergoing surgery for colon cancer(T4aN0M0, pStage Ⅱb). The patient had a history of prostate cancer 13 years prior (T3bN0M1)that was treated by hormone therapy after radiotherapy as well as post-myocardial infarction, post-parathyroid surgery, and type 2 diabetes. CEA, CA19-9, SCC, CYFRA, ProGRP, and PSA levels were within normal limits. Chest CT findings of the left lung revealed a 1.2 cm nodule in S3 and a 0.9 cm nodule in S9, with FDG uptake for both shown to be elevated in PET results. Based on examinations performed of frozen sections after performing a VATS wedge resection, the nodule in the left S3 was suspected to be primary lung cancer, while the left S9 nodule was considered to be metastasis from colon cancer. A VATS segmentectomy of the upper division was then performed. The diagnosis based on postoperative pathological results of the S3 and S9 nodules was metastatic lung tumor from prostate cancer and colon cancer, respectively. The patient is presently under observation without recurrence. Resection should be considered even when multiple lesions are present, as it is important to determine the primary tumor for deciding a treatment policy. Findings obtained in the present case indicate that an intraoperative rapid diagnosis procedure does not always provide accurate results for planning the best operative procedure.