A 76-year-old man with a past history of pneumoconiosis visited the Department of Gastroenterology in our hospital suffering from dysphagia. Gastroscopy revealed an esophageal ulcer on the top of a torus lesion. Chest computed tomography (CT) revealed it was caused by a swollen lymph node in the mediastinum. Squamous cell carcinoma related antigen (SCC) was elevated to 1.8 ng/ml. To rule out malignancy, we performed fluorine-18 deoxyglucose positron emission tomography (FDGPET) which revealed a significantly increased uptake in a nodular lesion in the right upper lobe and mediastinal lymph nodes. Biopsy and cytology of the nodular lesion revealed only pneumoconiosis. We must be careful when we interpret the findings of FDGPET in pneumoconiosis patients.