A 51-year-old woman visited our hospital with chief complaints of cough and fever. A chest X-ray detected an abnormal shadow in the right lung field. A chest computed tomography scan showed solid consolidation at S10 of the right lung. A blood test revealed elevated levels of the tumor markers, CEA(12.1 ng/ml), SLX (134 U/ml) and CA19-9 (76.2 U/ml). Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed abnormally increased 18F-FDG uptake with an SUV max of 11.29. Lung cancer was strongly suspected, and the surgery was performed. Abnormal blood vessels were found within the pulmonary ligament. Intraoperative rapid pathology indicated no malignancy, and the final diagnosis was pulmonary sequestration.