A lipoma is a harmless lump of fat. There are several different types, classified mainly by where they appear. The most common location is just beneath the skin, where they are easily felt, but they can occur anywhere.
Most tissues in the body can grow beyond their 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.
Lipomas have no known cause.
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.
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 (e.g., over a nerve) that it causes pain. Pain and redness may occur if it is frequently irritated.
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 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.
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:
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.
More commonly used to remove large quantities of fat from under the skin, this procedure can also remove single fatty tumors. Under local anesthesia (e.g., 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.
There are no preventive measures to avoid lipomas.