A lipoma is a benign tumor made of fat cells that usually appears as a soft lump under the skin, most often on the neck, back, shoulders, or arms. Although a lipoma can develop in deeper tissues, it is generally harmless and not linked to cancer.
A lipoma typically grows slowly and may not cause symptoms, but larger lumps can lead to discomfort, pressure, or visible changes in the skin. In rare cases, a lipoma may be confused with more serious conditions, making proper diagnosis important.
Most lipomas do not need treatment, but removal may be recommended if the lump is painful, grows quickly, or causes cosmetic concerns. Diagnosis is usually made through a physical exam or imaging tests, with surgery or liposuction used if needed.
Common symptoms
The main signs and symptoms of a lipoma include:
- A round lump under the skin, usually on the neck, back, shoulders, or abdomen
- A lump that is usually not painful, but may cause discomfort when pressed
- A firm, rubbery, or smooth texture
- A small lump that is usually around 5 cm, but can grow up to 10 cm or more
Lipomas can grow slowly over time without being harmful. However, larger lipomas may press on nearby tissues and cause pain, redness, or warmth in the area.
Can a lipoma be cancerous?
A lipoma is a tumor made of fat cells that usually forms beneath the skin. Lipomas are generally harmless and are not cancerous.
In very rare cases, a fatty tumor may be a liposarcoma, which is a malignant tumor that can grow in fat tissue and spread to nearby skin or muscles. Liposarcomas may cause symptoms such as pain, swelling, or rapid growth, and are more common in the arms, legs, and abdomen.
Confirming a diagnosis
A lipoma is usually diagnosed by a healthcare provider based on a physical exam. Imaging tests, such as ultrasound, MRI, or CT scans, may be used for larger or deeper lumps to confirm their characteristics and check if nearby tissues are affected.
According to the American Academy of Orthopaedic Surgeons, a biopsy is not often needed when imaging shows that the lump is made of fatty tissue, but it may be recommended if parts of the tumor look unusual.
Imaging or biopsy can also help distinguish a lipoma from other lumps, such as an epidermoid cyst, commonly called a sebaceous cyst, which forms from a buildup of keratin under the skin.
Possible causes
The exact cause of a lipoma is not fully understood. Lipomas can develop at any age, but they are more common in adults between 40 and 60 and are rare in children.
Some factors that may increase the risk of developing a lipoma include:
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Family history of lipomas
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Gardner syndrome
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Cowden syndrome
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Madelung disease
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Familial multiple lipomatosis, a condition that causes several lipomas to form, which may be large or painful
All lipomas should be evaluated by a dermatologist, especially if they grow quickly, become painful, or change in appearance.
Treatment options
Lipomas do not generally require treatment. However, surgical removal may be recommended if a lipoma is large, painful, interferes with daily activities, or causes cosmetic concerns.
1. Surgery
Lipoma surgery involves making a small incision in the skin, usually under local anesthesia. Very large lipomas may require general anesthesia.
The lump is then removed through the incision. This procedure is safe and effective, and lipomas rarely grow back after surgical removal.
Most people go home the same day. After surgery, the doctor may prescribe pain relievers or recommend ointments to help with healing and reduce scarring.
2. Liposuction
Lipomas can also be removed with liposuction. This procedure uses a thin tube or needle to remove fat cells from the lipoma and is usually done under local anesthesia.
Liposuction is effective and may allow for a faster recovery. However, the lipoma may be slightly more likely to grow back compared to surgical removal.