A lipoma is a common, non-cancerous growth of fatty tissue that develops just beneath the skin. It typically forms as a soft, movable lump and is considered a benign soft tissue tumor. These growths are generally harmless and usually do not cause health problems.
Understanding Lipomas
Lipomas are characterized by their distinct feel and appearance. They are typically soft and doughy to the touch, feeling rubbery rather than hard. When pressed with a finger, a lipoma will often move easily under the skin, indicating it is not firmly attached to underlying tissues. Most lipomas are small, commonly measuring less than 2 inches (5 centimeters) in diameter, though they can sometimes grow larger.
These fatty lumps can appear anywhere on the body where fat cells are present. They are most frequently found on the neck, shoulders, back, abdomen, arms, and thighs. While less common, lipomas can also develop in deeper tissues, such as within muscles or internal organs. They tend to grow slowly over months or even years. Genetics can play a role, with some individuals inheriting a tendency to develop them, and they are most often observed in adults between 40 and 60 years of age.
Lipomas and Cancer Risk
A common concern among individuals who discover a fatty lump is the potential for it to be cancerous or to become cancerous. Lipomas are almost universally benign, non-cancerous growths that do not typically transform into cancer. The risk of a lipoma becoming malignant is exceedingly rare.
It is important to distinguish between a common lipoma and a liposarcoma. Liposarcomas are malignant tumors that originate in fat cells. Lipomas are usually soft, movable, located just under the skin, and grow slowly. In contrast, liposarcomas often feel firmer, can grow rapidly, and tend to develop in deeper tissues or within the body. While a liposarcoma may occasionally mimic the appearance of a lipoma, they typically do not evolve from existing benign lipomas.
When to Seek Medical Advice
While lipomas are generally harmless, any new or changing lump should be evaluated by a healthcare professional. Seek medical attention if a lump rapidly increases in size, becomes painful, or changes in texture, such as becoming firm or immobile. Changes in the overlying skin, such as redness or warmth, also require evaluation. Lumps located deep within the body should also be assessed.
A healthcare provider will typically begin with a physical examination, feeling the lump to assess its characteristics, and may order imaging tests. An ultrasound is often the initial imaging choice for superficial lumps to assess their size, composition, and location. For larger or deeper lumps, or if the ultrasound is inconclusive, MRI or CT scans provide more detailed views to differentiate the lump from other soft tissue masses. In some cases, a biopsy may be necessary to confirm the diagnosis and rule out serious conditions like liposarcoma. Most lipomas do not require treatment unless symptomatic or cosmetically bothersome, but evaluation ensures an accurate diagnosis.