Desmoid tumors are rare, noncancerous tumors that grow in the body’s soft tissues. They can affect many parts of the body, including the abdominal wall.

MyDesmoidTumorTeam spoke with Dr. Seth Pollack, a sarcoma specialist in Chicago, to understand more about desmoid tumors in the abdominal wall. Dr. Pollack is the director of the sarcoma program at the Robert H. Lurie Comprehensive Cancer Center and the Steven T. Rosen Professor of Cancer Biology at Feinberg School of Medicine at Northwestern University.

Symptoms of Desmoid Tumors in the Abdominal Wall

If someone has a desmoid tumor in the abdominal wall they might “notice a mass, like a firmness … or they would feel pain,” Dr. Pollack said.

Dr. Pollack noted the importance of describing abdominal pain: “Sometimes if you’re just pointing to your belly and saying ‘I have pain there,’ the doctor’s going to interpret that as a stomachache.”

Make it clear that you’re feeling a mass or pain in the “superficial tissues” of your abdomen — that is, layers of tissue just beneath the skin — as opposed to gastrointestinal pain, he said.

Diagnosis of Desmoid Tumors in the Abdominal Wall

The first step to receiving a diagnosis involves talking to your doctor about what symptoms you’re experiencing. Your doctor may perform a physical exam and ask about your medical history.

Your primary care doctor may refer you to a specialist to help diagnose your tumor. Your doctor may order imaging tests like a magnetic resonance imaging (MRI) scan, a computed tomography (CT) scan, or an ultrasound. Imaging tests can show if you have a mass inside your body. A biopsy of the mass is needed to diagnose your exact condition. For a biopsy, your doctor will take a sample of your tumor tissue to be examined in a lab.

Abdominal Wall Desmoid Tumor Risk Factors

Certain factors may make you more likely to develop a desmoid tumor in the abdominal wall. These risk factors include:

• Pregnancy
• Trauma, such as abdominal surgery
• Familial adenomatous polyposis (FAP), a genetic disorder associated with colon cancer

Desmoid tumors are very rare. The vast majority of people who undergo abdominal surgery or who are pregnant don’t develop desmoid tumors. In addition, not everyone with FAP will develop a desmoid tumor.

Treatment Options for Desmoid Tumors in the Abdominal Wall

It’s important to get care from specialists with desmoid tumor expertise. These providers may be called sarcoma specialists. Sarcoma specialists are oncologists (doctors who specialize in diagnosing and treating cancer) who focus on treating sarcomas, which are cancerous tumors that can grow in the bones or soft tissues. Both soft tissue sarcomas and desmoid tumors are types of soft tissue tumors.

When talking about treatments with your desmoid tumor specialist, make sure you understand the goals of each potential treatment option and what you can expect from the treatment. Below are some possible care approaches your doctor may discuss with you.

Active Surveillance

“Historically, people were very aggressive surgically with desmoid tumors,” Dr. Pollack said. Today, surgery is not usually recommended as a first treatment because of the high chance the tumor will recur (return).

“Nowadays, if somebody has an abdominal wall tumor, we start by just observing them if they’re not having bad pain,” Dr. Pollack said. This observation may be called “active surveillance” or “watchful waiting.” If your desmoid tumor care team recommends this approach, you’ll have periodic scans to check your tumor.

Medical Therapy

“If their tumor grows, we usually start them on medical therapy,” Dr. Pollack continued, describing treatment for people with desmoid tumors in the abdominal wall. Medical therapy can include chemotherapy or targeted therapies that are taken as a pill.

Targeted therapies might include a tyrosine kinase inhibitor (TKI), such as sorafenib (Nexavar), or another type of targeted therapy called nirogacestat (Ogsiveo).

Dr. Pollack said he tends to treat people with targeted therapies more often than with chemotherapy. However, he noted that chemotherapy may be a good option for people who have difficulty with oral medications. He shared the examples of someone he treated with prior gastrointestinal issues and another person whose abdominal tumor affected their ability to eat.

Surgery and Other Treatments

According to guidelines from desmoid tumor experts, surgery may be an option for abdominal wall desmoid tumors that have progressed. The decision to undergo surgery should be considered by a multidisciplinary tumor board — a group of medical experts from different specialties.

Other treatments, such as cryoablation (using cold to damage and kill tumor cells) and radiation therapy, may be appropriate, depending on the individual’s circumstances.

Most desmoid tumor specialists no longer recommend hormone treatments like tamoxifen or nonsteroidal anti-inflammatory drugs (NSAIDs) for shrinking desmoid tumors. However, NSAIDs may still be used for pain.

Potential Complications of Abdominal Wall Desmoid Tumors

“The biggest complication that people have from desmoid tumors of the abdominal wall is really letting us treat them too aggressively,” Dr. Pollack said. When surgical treatment was the primary approach, “patients would have chronic problems from the surgery,” he said.

“You really do rely on your abdominal wall for your mobility and for being active. When you get surgery for the abdominal wall, a lot of the time it’s a big recovery because you can’t be as active. A lot of times you require physical therapy,” Dr. Pollack explained. He added that surgeries might require using surgical mesh to rebuild the abdominal wall’s firmness.

Dr. Pollack described how abdominal wall desmoid tumors might return after being removed: “It could come back with multiple tumors now because you’ve taken out the main tumor that was holding everything together and left little pieces, so they each could grow into their own tumors.”

These new tumors could potentially cause more problems than the original tumor. For example, Dr. Pollack noted, the tumors could grow into surgical mesh used in a previous surgery. Multiple tumors could also lead to more pain as they grow, he said.

Outlook With Abdominal Wall Desmoid Tumors

“Abdominal wall desmoid tumors don’t generally cause a life-threatening problem,” Dr. Pollack said. He noted that every year, he sees one or two people with severe complications, but that isn’t the norm.

When tumors require treatment, “we’re usually able to take people off medical therapy eventually,” Dr. Pollack said. He added that in many cases, “when we do take them off medical therapy, their tumor doesn’t start to grow again.”

Talk With Others Who Understand

MyDesmoidTumorTeam is the social network for people with desmoid tumors and their loved ones. On MyDesmoidTumorTeam, members come together to ask questions, give advice, and share their stories with others who understand life with desmoid tumors.

Do you have a desmoid tumor in the abdominal wall? Share your experiences and tips in the comments below, or start a conversation by posting on your Activities page.