A lipoma is a common growth made of fatty tissue that forms just beneath the skin.
What is a Lipoma?
A lipoma presents as a soft, doughy lump that typically moves easily when touched. These growths are generally painless, though some types containing blood vessels or pressing on nerves can cause discomfort. Lipomas are usually small, often less than 2 inches (5 centimeters) in diameter, and grow very slowly over time. They are encapsulated, meaning they do not spread into surrounding tissues.
Lipomas commonly appear in various areas of the body where fatty tissue is present, including the neck, shoulders, back, abdomen, arms, and thighs. While they can occur at any age, they are most frequently observed in adults between 40 and 60 years old. They are the most common type of soft tissue tumor found in adults.
Understanding Liposarcoma
There is a distinct type of cancerous tumor called a liposarcoma, which also originates from fat cells. It is important to understand that a liposarcoma is generally not the result of a lipoma transforming into cancer. Liposarcomas are rare, malignant tumors that can develop in any part of the body containing fatty tissue, often appearing deep within the abdomen, arms, or legs.
Distinguishing a liposarcoma from a typical lipoma involves recognizing several key differences in their characteristics. Liposarcomas tend to grow more rapidly and can reach larger sizes, sometimes exceeding 2 inches (5 centimeters) in diameter. Unlike the soft, movable texture of a lipoma, a liposarcoma may feel firm, fixed, or less mobile under the skin.
These cancerous growths can also cause pain, tenderness, or swelling, especially if they press on nerves or other tissues. Liposarcomas are classified into several subtypes, with well-differentiated liposarcoma being the most common. While some forms are slow-growing and may not spread quickly, others, such as pleomorphic liposarcoma, can be more aggressive and have the potential to spread to distant parts of the body, with their specific subtype and location influencing their behavior and symptoms.
When to Consult a Doctor
It is advisable to seek medical evaluation for any new or changing lump on the body. A healthcare professional can accurately diagnose the nature of a lump and determine if further investigation is needed. Specific indicators that warrant concern include a lump that is rapidly increasing in size, feels firm or hard, or is fixed in place and does not move under the skin.
Pain, tenderness, or changes in the lump’s shape or texture should also prompt a medical visit. If a fatty lump appears to be deep within the tissue rather than just under the skin, it is particularly important to have it checked. Diagnosis typically involves a physical examination, and often imaging tests like an ultrasound, MRI, or CT scan can provide more detailed information about the lump. In some cases, a biopsy, where a small tissue sample is taken for microscopic examination, may be necessary to confirm the diagnosis and rule out malignancy. While vigilance is important for any unusual growth, the vast majority of fatty lumps discovered are benign lipomas.