Lipoma (Fatty Tumor)

Definition

A lipoma is a harmless lump of fat. There are several different types, mainly classified by where they appear. The most common location is just beneath the skin, where they are easily felt, but they can occur anywhere.

Most tissue in the body can grow beyond its normal limits and form a lump or tumor. Tumors come in two forms: benign and malignant. Malignancies are referred to as cancers, which rarely stop growing. Benign tumors reach a certain size and then stop growing. Moles, polyps, and lipomas are examples of benign tumors. Some of these can turn into cancers, but lipomas do not.

Causes

Lipomas have no known cause.

Risk Factors

A tendency to grow lipomas seems to run in families. The only known risk factor is a hereditary condition called lipomatosis that produces many lipomas all over the body in both superficial and deep locations.

There is a rare disease called adiposis dolorosa that produces many painful lipomas.

Symptoms

The usual symptom is a soft lump under your skin that may range in size from a pea to a grapefruit. Although it is usually painless, the lump may be tender to touch. Rarely the lump is big enough or located in such a place (eg, over a nerve) that it causes pain. Pain and redness may occur if it is frequently irritated. A type of lipoma, called angiolipoma is frequently tender or painful.

Diagnosis Your doctor will ask about your symptoms and medical history, and perform a physical exam. The diagnosis is usually obvious from the smoothness, softness, and ease of movement under the skin. If there is doubt, it will be biopsied or imaged to confirm the diagnosis. A biopsy can be done by drawing a few cells from the lump with a needle and syringe under local anesthesia or by removing the entire lump by surgical excision. The resulting specimen is sent to the laboratory for identification. Treatment Talk with your doctor about the best treatment plan for you. You may want to leave it alone, although a rapidly-growing lump ought to be at least biopsied. Treatment options include the following: Surgical Excision Depending upon its location, this may be a simple office procedure or require an outpatient surgical facility. In any case, it is minor surgery unless the lipoma is deep inside the body. Liposuction More commonly used to remove large quantities of fat from under the skin, this procedure can also remove single fatty tumors. Under local anesthesia (eg, Novocain) a rigid tube is inserted through a button-hole incision into the fatty tissue under the skin and a strong suction is applied, sucking out chunks of fat.
Prevention There are no methods to prevent lipomas. RESOURCES: American Society of Plastic Surgeons http://www.plasticsurgery.org Penn State Milton S. Hershey Medical Center http://www.hmc.psu.edu CANADIAN RESOURCES: BC Health Guide http://www.bchealthguide.org The Canadian Society of Plastic Surgeons http://www.plasticsurgery.ca/ References: Lipoma. Penn State Milton S. Hershey Medical Center website. Available at: http://www.hmc.psu.edu/healthinfo/jkl/lipoma.htm . Accessed: July 8, 2005. Lipomaarm. Medline Plus Medical Encyclopedia website. Available at: http://www.nlm.nih.gov/medlineplus/ency/imagepages/1209.htm . Accessed July 8, 2005. Lipomas. The Merck Manual of Medical Information . Second Home Edition Online. Available at: http://www.merck.com/mmhe/sec18/ch215/ch215d.html . Accessed: July 8, 2005. Lipoplasty. American Society of Plastic Surgeons website. Available at: http://www.plasticsurgery.org/public_education/procedures/Lipoplasty.cfm . Accessed July 8, 2005. Salam GA. Lipoma excision. Am Fam Physician . 2002;65:901-904. Tompkins-McCaw Library for the Health Sciences, Virginia Commonwealth University website. Available at: http://www.library.vcu.edu/cfapps/tml/oralpathology/browse_oral.cfm . Accessed July 8, 2005.
Last reviewed January 2008 by Ross Zeltser, MD Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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