Diagnosis and Treatment - Desmoid Tumor Research Foundation

Diagnosis And Treatment

Mrinal Gounder, M.D. Melanoma and Sarcoma Service, Memorial Sloan-Kettering Cancer Center Scientific Director, The Desmoid Tumor Research Foundation


My name is Dr. Mrinal Gounder, M.D., and I am a medical oncologist practicing at Memorial Sloan Kettering Cancer Center in New York City. For more than a decade, I have devoted my efforts to building a clinical practice where I take care of a large number of people diagnosed with desmoid tumors. I am also the Scientific Director of DTRF. As a cancer researcher, I am passionate about finding a cure and discovering new drugs to treat desmoid tumors.

If you are reading this page, it is likely that you, your child or your loved ones may have been diagnosed with a desmoid tumor. It is normal to feel frightened, anxious, frustrated, confused or isolated. This is a very rare condition, but the good news is that you are no longer alone. We are here to help and support you. We hope that this web page provides you with information that will empower you and your doctor to make an informed medical decision together. We hope that the broader patient community of DTRF will be a safe space for you to meet other patients and their families – to connect and exchange your stories and experiences.

The good news is that this is often a treatable (and sometimes even curable) condition. I am happy to share that in the last decade – thanks to the Desmoid Tumor Research Foundation – we have been able to build a community of patients, their caregivers, doctors and researchers. This has helped gather a tremendous amount of knowledge about how best to treat desmoid tumors. Thanks in part to DTRF’s support for cutting-edge research, we are now seeing an exciting number of new drugs and modalities to treat this condition.

We are here to help and support you.

Dr. Mrinal Gounder


Read Dr. Gounder’s paper, “Locally Aggressive Connective Tissue Tumors” in the Journal of Clinical Oncology.

Please remember that desmoid tumors are very complex and the below information is a general overview and not intended as medical advice for any individual problem, or as a diagnosis, treatment plan, or recommendation for a particular course of action, and should not be used as a substitute for professional medical advice and services.  Please do not delay in seeking professional medical advice regarding your individual circumstances.


What is a desmoid tumor or aggressive fibromatosis?

We believe desmoid tumors arise from a cell called “fibroblast” or “myofibroblast”.  A fibroblast is a type of cell that is found throughout our body (head to toe) and is critical to keeping the entire structure of our body intact.  They are the structural support (scaffold) for all our vital organs (e.g. lung, liver, blood vessels, heart, kidneys, skin, intestines etc). We cannot survive without fibroblasts.

Fibroblasts are also involved in wound healing. For example, when we cut ourselves, the fibroblasts get activated and come together to heal the wound. Once the wound is healed, fibroblasts return to their resting state. Scientists believe that mutations in the DNA (which make up our genes) cause the fibroblasts to behave abnormally and turn into desmoid tumors. Therefore, desmoid tumors can arise in virtually any part of the body.

Desmoid tumors can be slow growing or aggressive. They do not metastasize (spread from one body part to another). For many patients, desmoid tumors are not life-threatening. However, when they are aggressive they can cause life-threatening problems or even death when they compress important organs such as intestines, kidneys, lungs, blood vessels, nerves, etc.


Desmoid tumors are rare.

In the United States, approximately 1,500 people are diagnosed with desmoid tumors every year. This means that out of a million people approximately 5-6 people are diagnosed with desmoid tumors each year. Experts believe that the numbers are likely to be far greater because of the difficulty in correctly diagnosing this disease. Because of inconsistent and inaccurate reporting procedures, accurate statistics about the number of desmoid tumor cases have not been kept. Individuals between the ages of 15 and 60 are most often affected, but this disease can occur in anyone including very young children. The average age is 20’s to 30’s. They are slightly more common in women than in men (2:1), and there is no significant racial or ethnic distribution.


Causes of desmoid tumors

The cause of most desmoid tumors is unknown and thus they are called “sporadic” or random. Most desmoids have mutations in a gene called beta catenin. A minority of desmoid tumors are caused by mutations in a gene called Adenomatosis Polyposis Coli or APC.

Patients with mutations in APC gene develop a condition called Familial Adenomatosis Polyposis syndrome or FAP. Patients with FAP are predisposed to forming hundreds of polyps in the intestines and – if untreated – go on to develop colon/intestine cancer. Patients with FAP are often recommended to undergo surgical removal of their colon or large intestines. These patients are at a very high risk of developing desmoid tumors (and other cancers). In older scientific literature, the combination of FAP and desmoid tumors is called Gardner Syndrome.

In some rare cases, desmoid tumors are diagnosed during or after a pregnancy. It is tempting to conclude that the changes during pregnancy (IVF, hormones, surgery) caused the desmoid tumor, however the scientific link is weak. Remember that pregnancy is extremely common, while desmoid tumors are extremely rare.


How do desmoid tumors behave?

Desmoid tumors behave in a wide variety of ways and it’s impossible to know how the disease will exactly behave in you.

As mentioned earlier, desmoid tumors can develop at virtually any site in the body. They can have a wide range of clinical symptoms or no symptoms at all. Many desmoid tumors are felt as a mass by patients and brought to medical attention, while others are accidentally picked up on a scan or a routine physical exam done for other medical reasons. Many people have no symptoms at the time of diagnosis or even after many years. Some people feel a range of symptoms that range from slight to severe pain, decrease in their movement or range of motion, swelling of the area affected by the desmoid tumor, loss of sleep, anxiety and many other symptoms.

Desmoids deep inside the abdomen or pelvis can also be entirely without symptoms or they can cause bloating, severe pain, rupture of intestines, compression of the kidneys or ureters or rectal bleeding. They can compress critical blood vessels such as the mesenteric vessels and the vena cava. It is important to know that the desmoid tumors that present superficially on the abdominal wall behave much differently than the ones that are deep inside the abdomen or pelvis.

One very interesting aspect of desmoid tumors is that on some occasions they can shrink or become quiescent (deep sleep) without any therapy.  Other desmoid tumors may be stable or grow very slowly over a period of months and years.  A small subset of desmoid tumors may be aggressive and grow rapidly. 

In conclusion, these tumors exhibit a wide range of behaviors and therefore their management is very different.



There are many non-invasive methods to evaluate a desmoid tumor which include ultrasound, CT and/or MRI scans. The actual diagnosis of a desmoid tumor can only be made after a small piece of the tumor is biopsied and examined under the microscope by a trained pathologist. The pathologist takes very fine sections of the biopsy material and examines them under the microscope looking for special features that define desmoid tumors.

There are no blood tests or non-invasive tests that can make the diagnosis. Depending on the location of the desmoid tumor your physician will recommend the optimal manner to biopsy it.

In rare circumstances, a biopsy may not be safe or feasible. When a biopsy is recommended, there are a variety of options which include: a core needle biopsy which takes a small piece, usually 1 mm wide by 10 mm long; and, surgical biopsies which may take a tiny portion of the tumor (“incisional biopsy”).

Your surgeon may recommend removing the entire desmoid tumor (“excisional biopsy”) in order to make a diagnosis and also to treat it. Prior to doing such a surgery to remove your tumor, it is extremely important that you discuss the short-term and long-term side effects of the excisional biopsy . In general, depending on location, surgery is not recommended for most desmoid tumors as a first-line treatment. (see below under “Surgery”). 


Imaging & Follow-up

Read more about MR Imaging of desmoid tumors.

Watch a video about the pathology of desmoid tumors. Although this video teaches about a few different sarcomas, desmoid tumors are shown between minutes 5:13- 15:09 in the video.



Read The Global Consensus Paper on the Management of Desmoid Tumors published in 2019.

If you are diagnosed with a desmoid tumor it is recommended that (if possible for you and allowed by your insurance) you be evaluated in a hospital with experts in sarcoma. These hospitals are usually designated as NCCN (National Comprehensive Cancer Network) centers but not all NCCN centers have expertise in sarcoma. Before making an appointment it is good to know whether they have experts in sarcoma. Ideally, patients with desmoid tumors should be evaluated by a multi-disciplinary team which includes medical oncologists, surgical oncologists, radiation oncologists, geneticists and nurses.

Here is a list of possible treatments:

  • Observation or “waiting and watching.” Desmoid tumors display a wide range of behaviors. This can range from shrinking spontaneously without any intervention, growing slowly, no growth or growing rapidly.  In some circumstances, it is reasonable to just watch the tumor carefully with images and/or physical examination. How often you need scans and/or physical exams during a “wait and watch” period will vary for each situation and your treating physician will discuss this with you.  A “wait and watch” approach is not right for everyone.


  • Surgery. Historically, most people with desmoid tumors underwent some form of surgery. Over several decades, it is increasingly being recognized that these tumors have a high risk of returning even with good surgery. While statistics may vary, about 25 to 60 percent of patients who undergo surgery can have a local recurrence (returning at or near the original site). The goal of surgery is to remove the entire tumor and minimize the risk of recurrence. Scientific research has shown that some types of desmoid have much higher risk of recurrence after surgery than others.

This can be calculated using an online calculator:

MSKCC nomogram

All nomograms are estimations and not always accurate. When making a decision to undergo surgery, you have to have an open conversation with your surgeon and medical oncologist about the risk of recurrence, time to recurrence and the short-term and long-term side-effects of the surgery. Increasingly, surgery is falling out of favor for desmoid tumors given their high risk of recurrence and other side effects. In some circumstances, surgery may be the best option and can result in great outcomes including a cure. In conclusion, the decision to undergo surgery is a complex one and should be weighted carefully.


  • Radiation Therapy. In general, many sarcoma experts do NOT recommend radiation for desmoid tumors. This is out of the concern for developing a new (aggressive) sarcomas due to the radiation. However, radiation therapy may be an effective option for a few patients in special circumstances. The dose and duration of radiation is highly variable and your radiation oncologist will discuss that with you. Both the short-term and long-term side effects from radiation should be carefully considered. In conclusion, the decision to undergo radiation is a complex one and needs to be discussed with your entire team.


  • Ablation. Ablation does not use radiation but rather heat (‘thermal”) or cold (“cryo”) to kill the desmoid tumor. This is an emerging technique where needles are inserted into the desmoid tumor and the tumor is “fried” or “frozen”. High-frequency ultrasound is a newly emerging technique which uses ultrasound waves to destroy the tumor. This is not invasive. Overall, this is a relatively new technique and the experience to date is limited to a few, specialized, medical centers, and the long-term results are not yet known. In conclusion, the decision to undergo ablation (hot, cold or ultrasound) is a very technical and complex one and needs to be discussed carefully with the interventional radiologist and your medical and surgical oncologist.

Learn more about high intensity focused ultrasound.


  • Medical Therapy. There is no single accepted medical treatment for desmoid tumors. Based on your medical health and nature of your desmoid tumor, your medical oncologist will discuss with you the best options for you. Numerous reports of individual cases show shrinkage or stabilization of tumor size or at least improvement in symptoms after a very wide variety of treatments. Chemotherapy is a chemical drug that is usually injected in the veins. A few chemotherapies that are commonly used include: doxorubicin, Doxil (liposomal doxorubicin), dacarbazine, methotrexate, vinorelbine and vinblastine. These chemotherapies can have a wide range of short and long term side effects. There have also been small studies using sulindac (non-steroidal anti-inflammatory) or anti-hormonal agents (tamoxifen). A new class of agents called tyrosine kinase inhibitors (e.g. sorafenib, pazopanib) has shown benefit in desmoid tumors by shrinking the tumors or slowing down the growth. These are pills taken by mouth at home.


Clinical Trials

While a great amount of progress has been made in our understanding of desmoid tumors, there is still a long road ahead.  While many therapies are available to treat desmoid tumors, there are new drugs being evaluated in clinical trials. Clinical trials are often a way to get access to a new modality or treatment but the decision to participate in a particular clinical trial should be carefully weighted. Not all clinical trials may be appropriate for you. Before you participate in a clinical trial talk to your team of doctors.

View all clinical trial information at clinicaltrials.gov


Articles on Past Clinical Trials