FDG PET/CT in a Case of Thoracic SMARCA4-Deficient Undifferentiated Tumor

Abstract

Thoracic SMARCA4-deficient undifferentiated tumor is a rare, newly recognized poorly differentiated tumor with poor prognosis. FDG PET/CT findings of thoracic SMARCA4-deficient undifferentiated tumor are rarely reported. We describe FDG PET/CT findings in a case of thoracic SMARCA4-deficient undifferentiated tumor. The tumor presented as a pleural mass, destroyed the adjacent ribs, and showed intense FDG uptake with SUVmax of 12.7. This case indicates that thoracic SMARCA4-deficient undifferentiated tumor should be included in the differential diagnosis of FDG-avid pleural lesions.

Occult SMARCA4-Deficient Undifferentiated Carcinoma Unmasked by 68Ga-FAPI-46 PET/CT

“…Previous studies have shown the usefulness of 18 F-FDG PET/CT in the evaluation of SMARCA4-dUT. 5,6 Recent studies have reported that 68 Ga-FAPI PET/CT may be useful for the diagnosis of SMARCA4-dUT and may even be more advantageous over 18 F-FDG for detecting metastatic lesions. 7,8 In this case, 68 Ga-FAPI-46 PET/CT detected the occult SMARCA4-dUT located in the left pulmonary hilum, which was not visualized by 18 F-FDG PET/CT.…”

“…Due to the rapid growth of SMARCA4-dUT, early diagnosis and accurate staging are crucial for patient management. Previous studies have shown the usefulness of 18 F-FDG PET/CT in the evaluation of SMARCA4-dUT 5,6 . Recent studies have reported that 68 Ga-FAPI PET/CT may be useful for the diagnosis of SMARCA4-dUT and may even be more advantageous over 18 F-FDG for detecting metastatic lesions 7,8 .…”