[A case of a resected metastatic lung tumor originating from testes which was difficult to diagnose preoperatively].

A 26-year-old man visited our hospital because of chest pain and bloody sputum. Chest X-ray showed a relatively round shadow with a border that was clear and smooth in the right middle lung field. The result of transbronchial lung biopsy (TBLB) revealed adenocarcinoma. The chest and body CT scans showed no abnormality except for this lung nodule. No lymphadenopathy was recognized, but chest wall invasion was also suspected from his symptoms. Right middle and lower bilobectomy and chest wall resection were performed. A pathological report showed metastasis to the lung from embryonal carcinoma. For young male patients, it is important to notice testicular malignant tumors besides the primary lung cancer.