Desmoid Tumor Explanations

A desmoid tumor is a tumor that forms on the muscle fascia. It belongs to the group of fibromatoses.

What is a desmoid tumor?

According to, fibromatoses are benign growths of the connective tissue that often grow very aggressively. They infiltrate their surroundings and often relapse even after surgical removal. The desmoid tumor develops from the envelopes of the muscles. These are also known as muscle fascia.

The desmoid tumor is actually benign, but since it often infiltrates the surrounding tissue, it is clinically classified as a low-grade sarcoma. The disease is very rare. Only 0.1 percent of all tumors are desmoid tumors. The incidence is one in four million. Women are affected significantly more often than men. The tumor often appears in the abdomen after pregnancy.

In children and adolescents, the tumor is more likely to develop in the arms, legs, head or neck area. Male children and adolescents get sick more often than girls. The tumors can regress spontaneously or they can continue to grow slowly. The neighboring organs are impaired by the growth, so that it comes to inflammation and functional impairment.


The causes of the desmoid tumor are largely unknown. A genetic predisposition was suspected for a long time. However, in most cases the tumors occur without a family relationship. However, there appears to be a connection between desmoid tumors and familial adenomatous polyposis (FAP).

This rare disease is characterized by multiple polyps in the lining of the colon and rectum. The polyps appear between the ages of 15 and 30 and often degenerate. Desmoid tumors occur regularly in connection with the disease. The tumors affect 10 to 15 percent of all patients with FAP.

It is also suspected that there are hormonal influences. This is supported by the fact that the tumors appear during pregnancy or shortly before menopause. At the time of menopause, many tumors regress spontaneously. Hormone receptors are present in the tumor cells. This suggests that oestrogens in particular can promote the development of tumors.

Injuries may also promote the development of desmoid tumors. In the scientific literature there are indications that the tumors can arise from scars. Many patients report that the tumors appeared for the first time after being physically injured. The exact mechanism of formation is still unclear here. Cellular dysfunction may occur during wound healing.

Symptoms, ailments & signs

The tumors can occur at any age and affect any muscle. They are noticeable through palpable swellings of different sizes and cause muscular, abdominal or neural pain. In some patients, the pain can be so severe that strong pain relievers are needed. The compression of organs or nerves can lead to functional disorders and inflammation.

Depending on the location of the tumor, the mobility of the body can be restricted. If the tumors coexist with polyps or sebum cysts, this suggests familial adenomatous polyposis. The disease usually progresses slowly. However, sudden growth spurts can also occur.

Further tumors can develop as the disease progresses. These are often localized in the vicinity of the original tumor, but can also appear in other parts of the body. Since the tumors are not subject to malignant changes, they do not metastasize.


If a desmoid tumor is suspected, MRI and CT scans are performed. Although the examinations allow a rough representation of the tumors, an exact definition of the limits is not possible. An exact determination is difficult, especially when the tumors are in the abdominal cavity. Thus, CT and MRI are used for the initial diagnosis.

This initial diagnosis must be confirmed by pathological examinations of a tissue biopsy. The tissue obtained from the tumor biopsy is examined histologically by a pathologist. This enables the characteristics of the tumor to be recorded. The histological examination reveals spindle-shaped cells that are separated by collagen tissue. The tumor is gray-white and has a coarse consistency. It rarely grows larger than five centimeters.


There is usually severe pain due to the desmoid tumor. Often this pain is so severe for the patient that pain medication must be administered. There may also be pain at rest, which occurs even without straining the muscles. Since this is a cancer, the further complications and complaints are heavily dependent on the time of diagnosis.

Mostly there is compression of the nerves or organs, which can lead to inflammation. It is also impossible to predict whether the symptom will progress slowly or quickly, so the patient needs regular examinations. The diagnosis is made with the help of an MRI. The need to remove the desmoid tumor depends on the status and spread of the cancer.

It is not necessary in all cases to remove the tumor. Unfortunately, the removal leads to mutilation in many cases, so that the patient is extremely restricted in his everyday life. Movement restrictions often occur and those affected not infrequently suffer from psychological complaints. Chemotherapy is usually also performed after the surgical removal. If the tumors are removed successfully, there will be no further complications and life expectancy will not be reduced.

When should you go to the doctor?

A doctor should be consulted quickly if there are unusual swellings that cause muscle pain or nerve disorders. These signs point to a desmoid tumor, which must be investigated and treated if necessary. Other warning signs that require clarification are functional disorders and inflammation of the muscles. Movement restrictions and a number of other complaints can also occur. Due to the variety of possible symptoms, a doctor should be consulted, especially if there is a predisposition.

Women are particularly at risk during pregnancy or shortly before menopause. People with familial adenomatous polyposis are also prone to desmoid tumors and should have the warning signs clarified at an early stage. If a sudden spurt of growth occurs, seek medical advice immediately. The same applies if severe pain occurs or a general feeling of malaise is noticed. A desmoid tumor can be treated well, but requires regular observation. Some tumors regress spontaneously, but a medical evaluation is still necessary.

Treatment & Therapy

For a long time, desmoid tumors were treated exclusively surgically. In the meantime, however, some surgeons and also oncologists are of the opinion that the removal of a desmoid tumor is not always absolutely necessary. Depending on the location of the tumor, an operation with complete removal of the tumor can result in mutilation.

Therefore, after a confirmed diagnosis, some doctors advise waiting and seeing whether the tumor continues to develop. Some tumors regress spontaneously or stop growing. Surgical treatment is particularly indicated when the tumor is localized. Embedded arteries, nerves and veins, on the other hand, pose a risk. Surgery should be avoided, especially in the case of mesenteric tumors.

There is a high risk of complications, so these tumors are usually treated with drugs. Usually anti-hormonal treatment with anti-estrogens such as tamoxifen is used. The anti-hormonal preparations are administered together with non-steroidal anti -inflammatory drugs. In this way, freedom from pain and symptoms can often be achieved.

However, drug therapy rarely causes the tumor to completely regress. It is currently being investigated whether radiation therapy can be an alternative to surgery. Radiation therapy could be particularly useful if surgery could not completely remove the tumor.

Outlook & forecast

The prognosis of the desmoid tumor is linked to the type of tumor disease and the size of the tumor. The greater the tissue change, the less favorable the further course of the disease and the prospect of a cure.

If the desmoid tumor is located within the abdominal cavity, threatening secondary diseases often occur. The risk of an intestinal obstruction is increased. This is a life-threatening condition. In severe cases, there is a risk of sepsis or hydronephrosis. The general life expectancy of the patient is shortened with these complications. If surgical interventions have to be performed repeatedly to remove the tumor, the risk of morbidity for the patient also increases.

If the desmoid tumor is outside the abdomen, the prognosis improves. In a surgical procedure, the tumor is usually removed and the patient is then discharged from treatment. A relapse occurs in around 70% of the observed cases. Since the recurrence rate of this disease is extremely high, check-ups should be carried out at regular intervals.

In addition, smaller desmoid tumors often form around an existing tumor. Surgical intervention is not performed in all cases. Depending on the location of the tumor, the consequences can be too drastic. If there is a risk of paralysis, doctors often decide against an operation.


Since the exact cause of desmoid tumors is unknown, prevention is not possible.


In the case of a desmoid tumor, the person concerned is primarily dependent on an early diagnosis and detection of this tumor so that there are no further complications or complaints. The earlier the tumor is detected, the better the further course of this disease is usually because it cannot self-heal either.

However, the measures and options for follow-up care for desmoid tumors are very limited, so that the person affected is always dependent on comprehensive treatment by a doctor first. In most cases, a desmoid tumor requires surgery. After that, the person concerned should definitely rest and take care of his body. Exertion or other stressful activities should be avoided in order not to unnecessarily burden the body.

In most cases, those affected with desmoid cancer also need the help and support of friends and family. Loving and intensive care also has a positive effect on the course of the disease. Even after the desmoid tumor has been successfully removed, regular examinations are advisable in order to detect other tumors at an early stage. This disease may also reduce the life expectancy of the person affected.

You can do that yourself

Therapy that is individually tailored to the patient is very important. Once treatment has taken place, a largely normal life can be led. This includes regular check-ups and, if necessary, appropriate follow-up treatments.

Pain may occur in connection with the disease. Here it is advisable to contact a local or national pain center in order to obtain advice on what to do in this case.

At the moment, no specific measures are known that would make it possible to prevent the first occurrence or recurrence of a desmoid tumor itself. For this reason, the recommendations for self-help are largely limited to leading a life that is as normal as possible and, if necessary, making contact with a patient organization and / or a self-help group.

A good contact for those affected is the SOS-DESMOID organization. Valuable information can be obtained here. It is also possible to exchange ideas with other affected persons. This is particularly important for diseases that are relatively rare. Knowing not to be alone can be very good, and even go a long way in improving your general wellbeing.

desmoid tumor