Fig. 1

SMARCA4-deficient thoracic tumor detected by [¹⁸F]FDG PET/CT. a Contrast-enhanced CT shows pleural thickening with abnormal enhancement. b Infiltration into the right anterior chest wall of the lesion (yellow arrow) can be observed. c Background emphysema is seen. d Maximum intensity projection of PET image shows multiple [¹⁸F]FDG-avid nodules in right thoracic areas. e–g PET/CT fusion axial images showing multiple [¹⁸F]FDG-avid nodules located in the pleura infiltrating into the chest wall. h Hematoxylin–eosin stain of the tumor biopsy specimen shows dense proliferation of atypical epithelial-like cells. i SMARCA4 stain is negative in tumor cells leading to a diagnosis of SMARCA4-deficient thoracic tumor