Pulmonary cryptococcosis is difficult to distinguish from lung cancer clinically, and is often diagnosed by surgery. A 72-year-old woman, who underwent distal pancreatectomy and splenectomy for pancreatic carcinoma. Four months after surgery, a tumor shadow was detected in the left lung as a groundglass nodule (GGN)of 12 mm in diameter, which was found to change to 15 mm with increased density by the computed tomography(CT)scan after 2 months. The nodule showed positive accumulation of fluorodeoxyglucose(FDG)by positron emission tomography(PET), and was suspected of malignant tumor. She underwent a partial resection of the left lung under thoracoscopy.