DR MOHAMMED IRFAN SHEIKH about 5 years ago

Hibernoma of the Neck

A 68-year-old man with no notable medical history presented with left cervical swelling that had been slowly increasing in size for 3 years. The patient was afebrile. The physical examination was unremarkable except for large swelling of the left side of the neck (Panel A), which caused limited mobility of the neck. The neck mass was firm, mobile, and nontender. There was no surrounding lymphadenopathy, and there were no signs of compression. Computed tomography revealed that the mass was heterogeneous and measured 27 cm by 16 cm by 17 cm (Panel B). A diagnosis of liposarcoma was considered, given the patient's age and the size of the mass. Histologic examination of a specimen obtained by surgical biopsy revealed features consistent with a hibernoma. Hibernomas are uncommon, benign soft-tissue tumors that histologically mimic brown fat. The most common anatomical locations of hibernomas are the neck, axillae, mediastinum, and periaortic and perirenal zones. The patient underwent total resection of the mass (Panel C); further histologic studies showed lobules of various sizes with many adipocytes and fat vacuoles and no atypical cells. At the 6-month follow-up, there had been no recurrence.