Abnormal FDG Uptake in the Pericardial Adipose Tissue Mimicking Malignancy

Focal mediastinal F-18 FDG uptake may be from potential adenopathy requiring biopsy confirmation or benign active brown adipose tissue to be left untouched. Knowledge of this potential pitfall and precise localization with fusion PET/CT are important in preventing misinterpretation as malignancy. Our case report is important in the aspect that CT was not able to confirm the uptake as benign finding, which led to invasive biopsy and biopsy confirmed it to be a benign brown adipose tissue. Case Report A 57-year-old woman was recently diagnosed with lung cancer. As part of the evaluation, PET/CT scan of the whole body was performed. It revealed high-grade uptake at the site of primary malignancy in the right lower lobe with a mean SUV of 7.8 (Fig. 1) and a 1