Cervical hibernoma, a rare, benign tumor: case report.

Hibernomas are rare, benign tumors that contain neoplastic cells that are histologically similar to those of brown adipose tissue. The most common sites of these tumors have been the back and thighs; head and neck involvement has been rare. We describe the case of a 54-year-old woman who presented with a 1-year history of a large, asymptomatic, lateral neck mass. Based on imaging findings and fine-needle aspiration cytology, a hibernoma was suspected, although a liposarcoma could not be ruled out prior to surgery. The mass was completely resected. On postoperative analysis, the tumor was grossly and microscopically consistent with a cervical hibernoma. Although hibernomas are rare, they are important entities and should be considered in the differential diagnosis of a soft-tissue mass of the head or neck.