Posterior MIP and additional selected axial and coronal images from a whole-body FDG-PET/CT demonstrate symmetric, markedly increased glucose metabolism in the neck, shoulders (arrows), and paraspinal regions (oval), as well as in the superior mediastinum and right upper abdomen (circle).

Differential Diagnosis

•  Brown adipose tissue (BAT) hypermetabolism: Characteristic, symmetrically increased activity in the neck, shoulders, upper mediastinum, and paraspinal locations makes this the most likely diagnosis.

•  Non-Hodgkin lymphoma: