False positive 18F-FDG PET/CT findings mimicking malignant disease in patients with pneumoconiosis (due to three case reports)

Besides the risk of developing pneumoconiosis and chronic obstructive pulmonary disease, potential lung cancer risk may also increase due to exposure to silica and other carcinogens. Patients with hemoptysis symptom referred to our clinic depending on different forms of mass images in their thorax computerize tomography (CT) scan with the suspicion of coal-worker pneumoconiosis and lung cancer were hospitalized for investigation and treatment. The results of routine tests, sputum acid-fast bacilli and sputum cytology were evaluated as normal. PET/CT was ordered from patients for identifying malignancy. In PET/CTs of the patients, a pathological level of 18F fluorodeoxyglucose uptake was identified in different forms of mass images observed previously in thorax CTs. All the pathological specimens obtained by fiberoptic bronchoscopic biopsy and/or by mediastinoscopy were reported as benign. We aimed to present three pneumoconiosis patients with false positive PET/CT findings in the light of relevant literature. As a result, we thought that pneumoconiosis must be in mind also when considering about false positive results of PET/CT.