Thoracic SMARCA4-Deficient Undifferentiated Tumor Mimicking a Pleural Mesothelioma on 18F-FDG PET/CT

Abstract

A 72-year-old woman, who was a nonsmoker, presented with chest distress persisting for over 10 days. Plain chest CT revealed thickening of the left pleura accompanied by hydrothorax. Subsequent 18F-FDG PET/CT showed irregular thickening involving the visceral, parietal, and interlobular pleura on the left side, with diffuse high avidity of 18F-FDG. The left pleural mesothelioma was suspected initially, but pathological examination from biopsied specimen later confirmed a thoracic SMARCA4-deficient undifferentiated tumor.