Unsuspected Bladder Diverticulum Resulted in False-Positive 68Ga-DOTATATE Uptake.

A 67-year-old woman with medullary thyroid cancer was referred for a 68Ga-DOTATATE PET/CT scan for staging. The images showed abnormal activity in the left thyroid gland and the left cervical lymph nodes. Surprisingly, increased activity was also noted in the posterolateral aspect of the urinary bladder without corresponding anatomical abnormality. This activity disappeared after urination, suggesting false-positive uptake due to bladder diverticulum.