[Positron emission tomography (PET)-computed tomography (CT) suggesting small intestinal metastasis from lung cancer; report of a case].

A 75-year-old man admitted to our hospital due to an abnormal X-ray shadow detected during an annual health check-up. Chest computed tomography (CT) revealed 3.0 cm solid nodules with chest wall invasion in the left lung. We could not get a definitive diagnosis by transbronchial lung biopsy or CT-guided needle biopsy. Positron emission tomography (PET)-CT revealed positive findings in the tumor, aortopulmonary window lymph node and splenic flexure. Under a diagnosis of suspected lung cancer, thoracotomy was performed. As intraoperative diagnosis revealed a moderately differentiated squamous cell carcinoma, the patient underwent a left upper lobectomy, mediastinal lymph node dissection, and combined chest wall resection. Pathological stage was T3N2M0, stage IIIA. Ten days after surgery, the patient suffered from ileus and emergent surgery was performed. Subsequent pathological examination revealed lung cancer metastasis in the small intestine.