Lipomas are not cancers, according to WebMD, and they are not dangerous. Most people who have them find that the worst aspects of lipomas are that they can become unsightly or interfere with their ability to move freely.
A lipoma is a capsule filled with fat cells that can be felt just beneath the skin, according to WebMD. They have a rubbery feel and can be moved around somewhat. They are painless and usually found on the upper thighs, arms, armpits, neck and torso. A person can have more than one lipoma, and they don't turn cancerous. A cancer comprised of fat cells is a liposarcoma, according to the American Academy of Orthopaedic Surgeons.
A dermatologist can usually tell if a growth is a lipoma through a simple examination. However, some may decide to biopsy it to make sure that it is not malignant, according to WebMD.
The cause of lipomas is unknown, according to the American Academy of Orthopaedic Surgeons. However, some medical experts believe that they are inherited and occur more often in sedentary people.
If a lipoma becomes troublesome, a doctor may decide to excise it, as noted by the American Academy of Orthopaedic Surgeons. This procedure can be performed in the doctor's office under local anesthesia.