A 76-year-old woman was referred to our hospital due to abnormal chest radiography findings. Chest computed tomography (CT) revealed a nodule in the right lower lobe. Fluorodeoxyglucose-positronemission tomography (FDG-PET) showed abnormal accumulation in the nodule. Bronchoscopy did not provide a definitive diagnosis. Since the nodule tended to increase in size, primary lung cancer was suspected and surgery was performed. During the surgery, pathological diagnosis of squamous cell carcinoma was made, and a right lower lobectomy was performed. Subsequently, a pathological diagnosis of mixed squamous cell and glandular papilloma (mixed papilloma) was made. She has had no sign of recurrence for approximately four years since the surgery.