[Lung Cancer Diagnosed as Primary Site Two Years after the Resection of the Thoracic Wall Cancer of Unknown Primary]

A 73-year-old man was referred to our department because of the left chest wall tumor. Computed tomography(CT) showed a chest wall tumor. The chest wall resection was carried out and the tumor was diagnosed as metastatic squamous cell carcinoma of unknown primary. The elevated serum level of carcinoembryonic antigen (CEA) was normalized after the surgery. Two years after the resection, the serum level of CEA elevated again and CT showed the pulmonary tumor 20 mm in diameter in the left upper lobe adjoining to the mediastinal pleura. The partial resection of the left upper lobe with mediastinal pleura was carried out. Pathological examination revealed this tumor to be the primary site of the previously resected chest wall tumor.