Hibernoma: diagnostic and surgical considerations of a rare benign tumour

Hibernoma is a rare, benign tumour of brown fat origin. Less than 250 cases have been reported in the literature. We present a case of a 19-year-old man referred to surgical oncology for evaluation of a large soft tissue mass near the apex of his right scapula. Complete surgical excision was performed, sparing the overlying latissimus dorsi musculature. Surgical pathology revealed findings were consistent with hibernoma, grossly showing a well-encapsulated fluctuant mass measuring 21.4×14.4×5.3 cm, and histologically composed of brown fat adipocytes. The mainstay of treatment is surgical excision of the mass. Primary goals of the operation include complete removal of the mass to prevent recurrence and sparing of adjacent structures as it is a benign, non-invasive tumour. We present a case of a large chest wall hibernoma in a young adult, diagnosed on final pathology after complete surgical excision.