A lipoma is a common, harmless growth of fatty tissue that develops just under the skin. Many individuals become concerned about these lumps, wondering if they can spread or transform into something more serious. This article clarifies the nature of lipomas and when medical advice is needed.
What is a Lipoma?
A lipoma is a non-cancerous lump of fat cells beneath the skin. They typically feel soft, rubbery, and are easily movable. Lipomas are generally painless, though some can cause discomfort if they press on nerves or contain blood vessels.
Lipomas can appear anywhere on the body where fat cells are present, but they are most commonly found on the neck, shoulders, back, abdomen, arms, and thighs. Most lipomas are small, typically less than 2 inches (5 cm) in diameter, but some can grow larger. They are benign soft tissue tumors that are not cancerous.
Do Lipomas Spread or Become Malignant?
Lipomas are encapsulated growths, contained within a thin, fibrous covering that prevents them from invading surrounding tissues or spreading. Unlike cancerous cells, lipoma cells do not metastasize, which is the process by which malignant cells spread through the bloodstream or lymphatic system. While a person might develop multiple lipomas, these are separate, new formations and not an indication that an existing lipoma has spread.
Lipomas are almost always benign and rarely become cancerous. The concern about malignancy often arises from confusion with liposarcomas, a rare type of cancerous tumor originating from fat cells. However, liposarcomas are distinct, aggressive cancers that behave differently from benign lipomas and originate through different biological pathways. They are not simply lipomas that have “turned bad”.
When to Consult a Doctor
While lipomas are typically harmless, any new or changing lump should be evaluated by a healthcare professional. A doctor can accurately diagnose the lump, which is important to rule out other conditions that might present similarly. This ensures proper identification and appropriate management.
Prompt medical attention is warranted for lumps with rapid growth, new or increasing pain, tenderness, or changes in color or temperature. Lumps that feel firm or hard, are immobile, or appear fixed to underlying tissues should also be checked. Consulting a doctor provides peace of mind and ensures that any potentially serious condition is addressed early.