Lipomas are the most common type of benign, soft tissue tumor. The growths generally develop between the skin and the muscle below, corresponding to where fat grows in the soft tissue. Though mostly harmless, lipomas can be painful and should be examined by a doctor if the individual is concerned or if the tumor is growing rapidly.
Risk Factor: Genetics
Though experts are unsure what specifically causes lipomas, they have identified several risk factors, one of which is genetics. Lipomas tend to run in families, and a family history of the growths could increase a person’s chance of developing them.
Risk Factor: Age
Another risk factor for lipomas is age. The growths are more likely to affect older adults between the ages of 40 and 60. Though anyone can develop a lipoma, they are rare in children and adolescents. Some studies suggest that lipomas are more common in males, although either gender can develop them.
Risk Factor: Other Syndromes
Certain disorders can increase the likelihood of developing a lipoma. Cowden syndrome, Gardner’s syndrome, and adiposis dolorosa can lead to multiple fatty lumps under the skin. Madelung’s disease is a rare illness that affects how the body stores fat and is another condition that can cause lipomas. In addition, several rare conditions increase the likelihood of developing these fatty tumors.
Symptom: Soft Lump under the Skin
A lipoma can appear anywhere on the body, though the most common locations are on the neck shoulders, back, arms, abdomen, and thighs. To the touch, lipomas are usually soft and may move around the area. Though lipomas are almost always benign, anyone who notices a lump growing under their skin should see a doctor to make sure.
Lipomas are generally small, less than two inches in diameter, though they can grow much larger in rare cases. Growths larger than four inches are categorized as giant lipomas. People prone to these benign tumors often develop multiple small growths.
Pain Due to Location
Lipomas are normally harmless, but they can cause pain if they are positioned over a nerve. Those that develop many blood vessels can also be painful, and this characteristic is most common in deeper lipomas. Rarely, the growths develop inside muscles and organs. Liposarcoma, a malignant lipoma, is a rare, fast-spreading type of cancer. If a doctor suspects a problematic lipoma, he or she will biopsy the lump and send a piece of it for testing.
Treating Lipomas: Monitor Growth
In most cases, a soft bump under the skin does not require medical treatment, though the doctor will likely recommend the patient continue monitoring the lipoma and return if it continues to grow or causes pain.
Treatment: Steroid Injections
Steroids can help shrink fatty tumors like lipomas, and a doctor may recommend this treatment for a problematic growth before turning to surgery. Steroid injections do not get rid of lipomas entirely, but they can shrink the lump, reducing its visibility and possibly any associated pain. They are most effective for lipomas under one inch in diameter.
Liposuction uses a syringe and needle to draw the fatty deposit of the lipoma from beneath the skin. This treatment is only recommended for certain types and locations of lipomas, however. In the case of giant lipomas that cause considerable pain, the doctor will likely recommend removal.
Surgery to remove a lipoma is done under local anesthesia, administered to numb the growth and the area around it. The outpatient procedure should not cause the patient any pain, and they can usually go home afterward. Over-the-counter painkillers can address any pain that develops after the anesthesia has worn off. The patient will return to the hospital or clinic a week or so later to have the stitches removed. Some people develop a scar or bruise. After removal, it is rare for a lipoma to recur in the same area.