Cervical hibernoma demonstrating uptake on Tc-99m lymphoscintigraphy

A hibernoma is an uncommon, benign tumor composed of brown adipose tissue. It is a rare but documented cause of neck masses. Hibernomas may be first diagnosed not by clinical examination, but incidentally through radiologic tests assessing the metabolic activity of certain tissues. These tumors are by definition benign entities but, given their propensity for growth over time, they require complete extirpation to prevent recurrence. Different radiologic modalities have been used to evaluate hibernomas, including computed tomography scan, magnetic resonance imaging, fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography, and angiography. It is rare for a hibernoma to be discovered through Tc-99m lymphoscintigraphy.