A desmoid tumor in your shoulder can cause a firm, swollen bump and make it difficult to move your arm. Desmoid tumors are benign (noncancerous) tumors that develop in the body’s connective tissue. Connective tissue refers to tissues that connect, bind, support, or separate tissues and organs.

Desmoid tumors can grow in many parts of the body. They are most often found in the extremities (arms and legs) and superficial trunk (the surface of the chest and back). In some cases, they form deep inside the belly in what’s called the abdominal cavity.

Desmoid tumor is a very rare condition. The National Cancer Institute estimates that each year, 2 to 4 people per million are diagnosed worldwide.

If you’ve been diagnosed with desmoid tumor or you suspect that might be what’s affecting your shoulder, here’s what you need to know about symptoms, diagnosis, and treatment options.

What Is a Shoulder Desmoid Tumor?

A shoulder desmoid tumor is an abnormal growth in the shoulder. It usually develops as a single tumor, but it’s possible to have several tumors.

Desmoid tumors are considered locally aggressive, meaning they do not spread to other areas of the body as cancerous tumors do. However, they can grow into surrounding tissues, causing pain and movement problems. Desmoid tumors may grow slowly or quickly, and the faster they grow, the more serious they usually are.

A desmoid tumor in the shoulder is rare. They are most likely to occur in people in their 30s or 40s but can develop at any time, starting during the teen years.

Symptoms of a Shoulder Desmoid Tumor

Symptoms of a shoulder desmoid tumor can vary. Some tumors do not cause symptoms, while others cause significant pain. The most common desmoid tumor symptoms include:

• A solid mass — You may notice a solid, swollen mass in your shoulder. It may feel like a hard lump in or around the shoulder.
• Pain — When the tumor presses on tissues and blood vessels in the shoulder, it can cause pain. This is the most common symptom of any desmoid tumor.
• Loss of motion — If the tumor grows, it may keep you from moving your shoulder and arm. Chronic pain from the tumor can also affect range of motion.
• Disrupted sleep — The pain from a desmoid tumor may impact your sleep.

How Is a Shoulder Desmoid Tumor Diagnosed?

Desmoid tumor is rare, and it is essential to see a doctor who specializes in diagnosing and treating the condition. Seek out a sarcoma specialist (a type of oncologist) who specializes in treating connective tissue tumors.

Many people with desmoid tumor face challenges in receiving the correct diagnosis. It may take a long time and many trips to different specialists and sometimes people receive an incorrect diagnosis first. This is often due to providers lacking expertise in this very rare condition.

To diagnose a shoulder desmoid tumor, your healthcare provider will conduct imaging tests to locate the tumor. If you develop pain and swelling in your shoulder, your provider may order a CT scan, MRI, or ultrasound to determine if there is a tumor and exactly where in the shoulder it is located.

If the imaging test reveals a tumor, your provider may recommend a biopsy. A biopsy is a test that uses a tissue sample to examine it for cancer cells and other signs of disease. A pathologist will then review the biopsy results to determine what kind of tumor you have.

How Is a Shoulder Desmoid Tumor Treated?

There are several treatment options available for a desmoid tumor in the shoulder. When determining your treatment plan, your healthcare team will consider the exact location of your tumor, how fast it’s growing, your symptoms, and your overall health.

Active Surveillance

In some cases, your healthcare team may recommend monitoring the tumor and waiting to treat it. This is appropriate for tumors that are slow growing and not causing pain or other symptoms. In up to 20 percent of cases of desmoid tumor, the tumors may shrink on their own without treatment. This is known as spontaneous regression, and the tumor may disappear completely.

During active surveillance, notify your healthcare team if you experience any new symptoms, because this could mean that the tumor is growing and you require additional treatment strategies.

Targeted Therapies

Targeted therapies are medications and treatments that target specific proteins or other compounds in tumor cells. These therapies can affect how tumor cells grow and multiply, keeping the tumor from getting larger or spreading into nearby tissues.

Chemotherapy

Chemotherapy uses powerful drugs that kill fast-growing cells. It is a common cancer treatment that may help shrink desmoid tumors.

Radiation Therapy

Radiation therapy uses high-energy beams to kill cells and shrink a tumor. It may be helpful for certain types of shoulder desmoid tumors. However, radiation therapy may cause cell damage that raises the risk of future cancers so it’s not often a first choice for desmoid tumor treatment.

Surgery

In some instances, your healthcare provider may recommend surgery to remove the tumor. While surgery used to be a standard treatment, it is no longer recommended in most cases. That is because desmoid tumors recur frequently, meaning they can grow back after removal. It is challenging to fully remove a desmoid tumor, and it’s not usually recommended for the shoulder.

Living With Shoulder Desmoid Tumor

Receiving a desmoid tumor diagnosis can be overwhelming. This rare tumor can significantly affect your quality of life. Finding the right treatment course is challenging, and there is a high rate of recurrence.

When a desmoid tumor causes severe pain in the shoulder, it may impact your entire life, especially your ability to move around independently. These symptoms may affect your emotional well-being and mental health.

Research shows that pain is the symptom of desmoid tumor that most significantly affects quality of life. Chronic pain may lead to anxiety and depression over time. It is critical to advocate for your care and tell your provider when your pain increases. There are treatment options available to improve your pain and possibly shrink the tumor. Continue to follow up with your healthcare team if your pain is not manageable.

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