Extensive hypermetabolic pattern of brown adipose tissue activation on 18F-FDG PET/CT in a patient diagnosed of catecholamine-secreting para-vesical paraganglioma.

The widespread use of (18)F-FDG PET-CT scanning in oncological patients has allowed to demonstrate the existence of metabolically active brown fat, also called brown adipose tissue (BAT), in adult humans, and specifying its anatomical distribution in vivo. As physiological determinants to BAT (18)F-FDG uptake has been identified gender, age, temperature, and body mass index. We have observed extensive activation of the BAT, including the mesenteric region, in a patient with a catecholamine-secreting para-vesical paranganglioma. The extensive BAT activation could be secondary to adrenergic stimulation due to excess of circulating norepinephrine concentration.