Hibernoma with metabolic impact?

A hibernoma is a benign tumour of brown adipose tissue (BAT). BAT is also present in physiological depots, previously considered residual. However, in 2009 functional BAT in adults was reported. Metabolically active BAT is suggested to significantly influence the energy balance and increasing BAT activity could possibly treat obesity. This strongly increased the interest in BAT in man and currently more research is conducted. We describe the case of an intramuscular hibernoma and illustrate the pathophysiology of the observed hibernoma in relation to recent insights on physiological BAT. Immunofluorescence staining of the hibernoma showed the presence of uncoupling-protein-1, a protein specific for active BAT. This suggests that this hibernoma contains BAT that could possibly contribute to the human energy balance.