There are two causes of abdominal lipomas, which are benign tumors made up of fatty tissue. The first is a genetic mutation, while the second is a heredity condition known as lipomatosis that causes the appearance of multiple lipomas. One of these lipomas can appear just under the skin in the subcutaneous layer or within the muscle wall, which may cause discomfort and require surgical removal.
Though a lipoma is a tumor, a collection of cells that continually divide, it is not malignant. This means that the cells of a lipoma cannot travel to other organs and tissues and create new tumors. An average abdominal lipoma grows to between 0.39 and 0.78 inches (1 and 2 cm) in diameter and is hard to the touch. Depending on the particular subtype of lipoma, touching it can produce pain.
The first cause of an abdominal lipoma is a genetic mutation. All cancers begin when a genetic mutation in a single cell causes it to continuously replicate rather than undergo programmed cell death. In the case of lipoma, these cells are always fat cells, which gather into a single tumor. Though most examples are small, some can continue to grow to the size of a fist or larger.
The second cause is lipomatosis. This is a heredity condition that causes multiple lipomas to develop throughout the body, mainly in the trunk. The appearance of multiple tumors is not a sign of malignant cancer, but rather a disposition to lipomas appearing in several places simultaneously. These tumors, if they appear in the subcutaneous layer, can cause visible bumps that may be cosmetically unappealing to the patient.
Diagnosing an abdominal lipoma requires a physical examination and X-rays. A physical exam gives a patient's healthcare provider the opportunity to feel the lipoma, while the X-ray provides visual confirmation. Imaging may also discover a second or third unnoticed lipoma in the abdomen. If a patient does not physically notice the lipoma, no treatment is necessary other than checking to see if it has grown during annual physical examinations. Ones that are large and/or is situated between the abdominal muscles may require surgery to avoid complications, such as tenderness or pain.
Surgical removal of the lipoma can be achieved through a variety of techniques. Simple resection requires a small cut into the skin and the tumor is removed in one piece. Endoscopic removal, using a miniature camera and minor incisions, can achieve the same effect if the lipoma is small enough. Liposuction, which involves breaking the lipoma into small pieces within the body before sucking them out through a tube, can also be performed. Once removed, abdominal lipomas generally do not grow back.