Desmoid tumors are rare, noncancerous, soft tissue tumors that can develop in any part of the body. They usually grow slowly and tend to recur (come back) after treatment. Specific symptoms and treatments for desmoid tumors depend on where the tumor is located.

A desmoid tumor diagnosis can be overwhelming. This article will help you learn what you need to know about location-specific symptoms and treatments of desmoid tumors.

Intra-Abdominal and Abdominal Wall

Desmoid tumors can form in the abdominal wall or inside the abdomen (intra-abdominal). Intra-abdominal desmoid tumors occur in the connective tissue surrounding the intestines (mesentery). Tumors in the abdominal wall grow in the tissue surrounding the abdomen.

In a study of 179 people with desmoid tumors, 40 percent had tumors in the abdominal wall. Another 8 percent had tumors in the abdomen or the retroperitoneal space (the area behind the abdomen).

When desmoid tumors grow in the abdomen, they can press on nearby organs like the stomach and intestines. This can lead to cramping, vomiting, and nausea.

For abdominal wall or intra-abdominal desmoid tumors, doctors usually recommend active surveillance, also called watchful waiting. Your doctor will monitor your tumor over time and only actively treat it if necessary. Many desmoid tumors spontaneously shrink, disappear, or remain small enough not to cause symptoms. Active surveillance can prevent unnecessary treatment. If active treatment is needed, the specifics will depend on the size and location of your tumor.

Treatment for Abdominal Wall Desmoid Tumors

Abdominal wall tumors grow in the tissues around the abdominal wall cavity, surrounding the organs in the abdomen. Because the tumors are located in the outer tissues, they can cause a lump or swelling that is hard to miss.

Abdominal wall tumors can sometimes be linked to pregnancy. Desmoid tumors can be caused by injury (such as surgery) to the area. Cesarean section (C-section) and the stretching of the abdominal wall during pregnancy are both thought to be potential causes for desmoid tumors. Additionally, pregnancy increases estrogen levels. Estrogen is a hormone associated with the development of desmoid tumors.

The primary treatments for abdominal wall desmoid tumors are surgery, medical therapy, or local treatments like cryoablation (freezing the tumor). The goal of these treatments is to remove, shrink, or stop the tumor from growing.

Treatment for Intra-abdominal Desmoid Tumors

Intra-abdominal wall desmoid tumors grow in the mesentery, the tissue that connects the intestines. Because these tumors are close to vital organs, they can be difficult to operate on. Unlike abdominal wall tumors, the lumps of intra-abdominal tumors are harder to see or feel. Treatment options for intra-abdominal wall tumors include surgery and medical therapy. However, the treatment approach may depend on whether the tumor is related to familial adenomatous polyposis (FAP) or Gardner syndrome.

FAP and Gardner syndrome are risk factors for developing desmoid tumors. About 10 percent of people with FAP will develop a desmoid tumor in their lifetime. Desmoid tumors in people living with FAP or Gardner syndrome are more likely to be intra-abdominal and infiltrative (spread into surrounding tissue).

Infiltrative tumors are harder to remove without damaging the nearby tissues and organs. Because of these risks, surgery is only considered in people with FAP when the tumor causes complications, like blockages or damage to the intestine. The goal of surgery is not to completely remove the tumor but to relieve complications caused by the tumor and prevent further damage.

Extra-Abdominal

Extra-abdominal tumors are those that occur outside the abdomen. In a study of 179 people with desmoid tumors, 49 percent had extra-abdominal tumors. These tumors can appear in the:

• Chest wall
• Back
• Neck
• Head
• Extremities (arms and legs)

Like desmoid tumors in the abdomen, extra-abdominal tumors are often monitored through active surveillance.

Chest Wall and Back

Chest wall and back desmoid tumors make up to 38.5 percent of desmoid tumors that aren’t in the abdomen, according to a study of 91 people. Chest wall and back desmoid tumors can be superficial (on the surface) or intrathoracic (within the thorax or chest). Superficial tumors are easy to feel as lumps under the skin. Intrathoracic desmoid tumors, on the other hand, may cause symptoms if they grow large enough to press on nearby organs. These symptoms can include difficulty breathing, chest pain, and coughing.

The treatment for chest desmoid tumors depends on their location. For superficial desmoid tumors, medical therapy or local ablative techniques are the primary treatment recommended. For intrathoracic tumors, your doctor will likely suggest medical therapy.

If these treatments aren’t effective, radiation therapy and surgery may be considered.

Head and Neck

Head and neck desmoid tumors make up 9.9 percent of desmoid tumors outside the abdomen, according to a study of 91 people. These tumors can cause lumps in the head or neck and may lead to functional restrictions (like difficulty closing the mouth).

Because head and neck desmoid tumors are close to the brain, doctors usually suggest treatment sooner to prevent complications. A tumor that keeps growing can quickly impact the brain. Desmoid tumors in the head and neck tend to be more aggressive in children, so they need to be monitored closely. However, active surveillance is still an option if the tumor is not growing.

Medical therapy is the first line of treatment for head and neck desmoid tumors. Other treatment options include surgery, radiation, and local ablative techniques.

Extremities

Desmoid tumors in the extremities — arms and legs — account for 23.1 percent of desmoid tumors outside the abdomen in the same study of 91 people. Symptoms for desmoid tumors in these areas can include lumps, difficulty moving, and pain.

Medical therapies and local ablative techniques are the primary treatments for these desmoid tumors. Secondary treatments include surgery, radiation, and isolated limb perfusion (ILP).

In some cases, the tumor may be too large to remove without affecting limb function. For desmoid tumors in the arms and legs, ILP can be used. ILP involves injecting a higher dose of medication into the affected limb. By cutting off circulation to the affected area, a higher dose can be safely used without affecting other organs. This treatment is possible for extremities, as no vital organs are deprived of oxygen during the procedure.

Find Your Team

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.

Are you living with desmoid tumors? How did your tumor location affect your diagnosis and treatment? Share your experiences in the comments below, or start a conversation by posting on your Activities page.