Most people who have a gastrointestinal lipoma have no idea that a benign tumor is growing in their colon. In general, these soft tissue masses do not cause any symptoms and remain small. They are typically diagnosed during a routine colonoscopy or when testing for symptoms caused by another condition. Rarely, however, they do need to be removed. This is often necessary for one of two reasons: either they cannot be accurately diagnosed without removal or they have grown large enough to cause other problems.
Why Would A Lipoma Require Removal For Diagnosis?
Since lipomas are most commonly discovered during a colonoscopy, either done for preventative care or to investigate unrelated symptoms, they are often also diagnosed during the imaging procedure. Frequently, these harmless small masses can be definitively diagnosed based on appearance alone. Using tools that fit within the scope, they can also be manipulated to test for firmness (the so-called “pillow sign”), and other factors. Lipomas usually move in distinctive ways that allow the doctor to rule out cancer or other harmful growths without removal.
In most cases, a lipoma will appear:
- Circular or ovoid in shape
- Has clean, smooth edges
- Soft when pressed (the “pillow sign”)
- Often yellowish
If the growth does not seem to be typical of a lipoma, then a malignant tumor cannot be ruled out. The doctor may recommend contrast imaging for a closer look. If a definitive diagnosis still cannot be made, removal will be necessary to ensure the mass is not cancerous. While this rarely happens, it often leads to the most invasive of lipoma removal operations. This is because the surgeon will be sure to remove enough tissue to get clean margins around the growth in case it is cancer. After removal, the mass is tested and the lipoma diagnosis can be confirmed by the laboratory.
What If A Lipoma Causes Symptoms?
About a quarter of large lipomas that form in the colon or other parts of the gastrointestinal tract cause symptoms. These growths are often larger than 2 centimeters in size, or located in an unusual area. A group of smaller lipomas may also cause the same type of symptoms that are seen with larger growths.
Symptomatic lipomas most frequently cause rectal bleeding and abdominal pain. Other symptoms may include constipation, difficulty voiding bowel movements or intussusception (the telescoping of the bowel into itself. The lipoma may act as a lead point).
Removal of the lipoma is the only way to stop most of these symptoms. If the symptoms are minor, your doctor may decide that removal is not necessary. About 25 percent of large growths, however, will probably require removal due to ongoing or severe symptoms. Leaving growths in place that are causing bleeding or intussusception could lead to weight loss, anemia, nausea, and other more severe problems.
Can Lipomas Be Removed Endoscopically?
During the course of a colonoscopy, lipomas may be treated in much the same way as colon polyps are treated. Lipomas that can be definitively diagnosed and are smaller than 2 cm can usually be removed endoscopically during the imaging procedure. Or, they may not be removed at all, depending on the judgment of your doctor. Colonoscopy is by far the most minimally invasive way to remove a benign growth, and recovery only involves eating a high fiber diet for a few days. The removed mass will then be sent to the lab to confirm the lipoma diagnosis and ensure there are no malignant cells present.
Some colon and rectal specialists may opt to remove larger lipomas during a colonoscopy. This depends on both the location of the tumor and the doctor’s preference. There is a greater risk of perforating the colon wall when removing lipomas larger than 2 cm, especially if the growth has a broad base. Injecting a saline solution into the base of the mass can help raise the mass and make it easier to remove, but is not always effective. Because this minimally invasive treatment has a risk of major complications, many doctors shy away from removing any growth larger than 2 cm endoscopically.
How Are Lipomas Surgically Removed?
Lipomas larger than 2 cm or those that cannot be definitively confirmed as benign are typically removed during a laparoscopic surgery. Some small tumors with broad bases may also need to be removed laparoscopically to reduce the risk of tearing the colon wall. Laparoscopic surgery uses several small openings in the abdomen to inflate the abdomen and insert a camera and tools. These tools are then used to remove a small section of the colon and stitch or suture the hole closed.
Using laparoscopic equipment to remove lipomas is preferred over traditional surgery because it requires several small incisions instead of a large incision which would take a long time to fully heal. Laparoscopy reduces the risk of complications, including bleeding. With laparoscopic surgery, patients are typically back to their regular activities in as few as 10 days, and have far less pain than those who have a larger incision. The bowels also typically recover faster, allowing the patient to return to a normal diet sooner.
As always, your colon and rectal surgeon will provide you with information to both educate you and relieve your anxiety.