by Jason Wasserman MD PhD FRCPC
March 11, 2023
A hibernoma is a non-cancerous tumour made up of brown fat. Brown fat is a type of fat that is normally found in newborns and young children but it disappears over time and most adults have very little brown fat.
No. A hibernoma is a non-cancerous type of tumour.
Hibernoma and lipoma are both non-cancerous tumours made up of fat. However, a hibernoma is made up of a specialized type of fat called brown fat that is normally only found in newborns and young children. In contrast, a lipoma is made up of ordinary ‘white fat’ that is normally found throughout the body in adults.
Most hibernomas are slow-growing masses that cause very few if any symptoms.
At this time doctors do not know what causes most hibernomas to develop. However, people with the genetic syndorme multiple endocrine neoplasia type 1 (MEN1) seem to be at higher risk for developing hibernomas.
This diagnosis is usually made after part or all of the tumour is removed and examined under a microscope by a pathologist.
When examined under the microscope, a hibernoma is made up of brown fat cells surrounded by thin blood vessels. The brown fat cells may be described as vacuolated because the cytoplasm (body) of the cell is divided into multiple parts. Mitotic figures (tumour cells dividing to create new tumour cells) and atypical cells (tumour cells that are abnormal in shape, size, or colour) should not be seen.