Desmoid Tumor: Causes, Symptoms & Treatment

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

What is a desmoid tumor?

Fibromatoses are benign growths of connective tissue that often grow very aggressively. They infiltrate their surroundings, and even after surgical removal, they often recur. Desmoid tumor develops starting from the sheaths of the muscles. These are also called muscle fasciae. Desmoid tumor is actually benign, but because it often grows infiltrating into the surrounding tissue, it is clinically classified as a low-malignant 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 occurs in the abdomen after pregnancy. In children and adolescents, the tumor is more likely to develop in the arms, legs, head or neck. Male children and adolescents develop the disease more frequently than girls. The tumors may regress spontaneously or continue to grow slowly. Neighboring organs are affected by the growth, resulting in inflammation and functional impairment.

Causes

The causes of desmoid tumor are largely unknown. For a long time, a genetic predisposition was suspected. However, in most cases, the tumors occur without a familial connection. Apparently, however, there is a connection between desmoid tumors and familial adenomatous polyposis (FAP). This rare disorder is characterized by multiple polyps in the mucosa of the colon and rectum. The polyps occur between the ages of 15 and 30 and frequently degenerate. Desmoid tumors regularly occur in association 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 occur during pregnancy or shortly before menopause. At the time of menopause, many tumors spontaneously regress. Hormone receptors are present in the tumor cells. This suggests that estrogens in particular may promote the development of the tumors. It is also possible that injuries favor the development of desmoid tumors. There is evidence in the scientific literature that the tumors may arise from scars. Many patients report that the tumors first appeared after a physical injury. However, the exact mechanism of origin is still unclear in this case. Possibly, cellular dysfunction occurs during wound healing.

Symptoms, complaints, and signs

Tumors can occur at any age and affect any muscle. They are noticeable by palpable swellings of varying sizes and cause muscular, abdominal, or neural pain. In some patients, the pain can be severe enough to require strong analgesics. Functional disturbances and inflammation may result from compression of organs or nerves. Depending on the location of the tumor, mobility of the body may be limited. If the tumors occur together with polyps or sebaceous cysts, this suggests familial adenomatous polyposis. The disease usually progresses rather slowly. However, sudden growth spurts may occur. During the course of the disease, additional tumors may develop. These are often localized in the vicinity of the original tumor, but may also appear in other areas of the body. Because the tumors do not undergo malignant transformation, they do not metastasize.

Diagnosis

MRI and CT scans are performed when a desmoid tumor is suspected. Although the examinations allow gross visualization of the tumors, accurate borderline detection is not possible. Especially if the tumors are located in the abdominal cavity, an exact determination is difficult. Thus, CT and MRI serve to establish the initial diagnosis. This initial diagnosis must be confirmed by pathological examination of a tissue biopsy. The tissue obtained from the tumor biopsy is examined histologically by a pathologist. This allows the characteristics of the tumor to be recorded. Histological examination reveals spindle-shaped cells separated by collagen tissue. The tumor is grayish white and has a coarse consistency. It rarely grows larger than five centimeters.

Complications

Because of the desmoid tumor, patients usually experience severe pain. Often, this pain is so severe for patients that pain medications must be administered. There may also be pain at rest, which occurs even when the muscles are not being strained. Since this is a cancer, further complications and discomfort are highly dependent on the time of diagnosis. Most often, there is compression of nerves or organs, from which inflammation can develop. It is also impossible to predict whether the symptom will progress slowly or rapidly, so the patient is dependent on regular examinations. The diagnosis is made with the help of an MRI. Whether removal of the desmoid tumor is necessary depends on the status and spread of the cancer. It is not necessary to remove the tumor in all cases. Unfortunately, in many cases, removal results in mutilation, leaving the patient extremely limited in his or her daily life. Movement restrictions often occur and those affected not infrequently suffer from psychological discomfort. After surgical removal, chemotherapy is usually also administered. If the tumors are successfully removed, no further complications occur and life expectancy is not reduced.

When should you go to the doctor?

If there is unusual swelling that causes muscle pain or nerve interference, a doctor should be consulted quickly. These signs indicate a desmoid tumor, which must be clarified in any case and treated if necessary. Other warning signs that require clarification are functional disorders and inflammation of the muscles. Similarly, there may be movement restrictions and a number of other complaints. 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 a family history of adenomatous polyposis are also susceptible to desmoid tumors and should have the aforementioned warning signs clarified early. If a sudden growth spurt occurs, a doctor must be consulted immediately. The same applies if severe pain occurs or a growing discomfort is noticed in general. A desmoid tumor can be treated well, but requires regular observation. Although some tumors regress spontaneously, medical clarification is still necessary.

Treatment and therapy

For a long time, desmoid tumors were treated exclusively by surgery. However, some surgeons and even oncologists now believe that removal of a desmoid tumor is not always mandatory. Depending on the location of the tumor, surgery with complete removal of the tumor may result in mutilation. Therefore, after confirmed diagosis, some doctors advise waiting and seeing if the tumor continues to develop. Some tumors spontaneously regress or stop growing. Surgical treatment is indicated primarily when the tumor is localized. Embedded arteries, nerves, and veins, on the other hand, pose a risk. Surgery should be avoided, especially for mesenteric tumors. There is a high risk of complications, so these tumors are usually treated with drugs. As a rule, anti-hormonal treatment is carried out with anti-estrogens such as tamoxifen. 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, the tumor rarely regresses completely as a result of drug therapy. Research is currently underway to determine whether radiation therapy can be an alternative to surgery. In particular, if the tumor could not be completely removed by surgery, radiation therapy could be beneficial.

Outlook and prognosis

The prognosis of desmoid tumor is tied to the type of tumor disease and the size of the tumor. The larger the tissue change, the less favorable the further course of the disease and the prospect of cure. If the desmoid tumor is located within the abdominal cavity, there are often threatening sequelae. The risk of intestinal obstruction is increased. Thus, a life-threatening condition exists. In severe cases, there is a threat of sepsis or hydronephrosis. The general life expectancy of the patient is shortened with these complications.If repeated surgical procedures have to be performed to remove the tumor, the risk of morbidity for the patient also increases. If the desmoid tumor is located outside the abdominal cavity, the prognosis improves. In a surgical procedure, the tumor is usually removed and the patient is subsequently discharged from treatment. Recurrence occurs in approximately 70% of observed cases. Since the recurrence rate of this disease is extremely high, control examinations should be performed at regular intervals. In addition, other 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 after-effects can be too drastic. If there is a risk of paralysis, doctors often decide against surgery.

Prevention

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

Follow-up care

In the case of desmoid tumor, the affected person is primarily dependent on early diagnosis and detection of this tumor to avoid further complications or discomfort. The earlier the tumor is detected, the better is usually also the further course of this disease, since it can also not come to a self-healing. However, the measures and possibilities of aftercare for desmoid tumors are very limited, so that the affected person is always dependent on comprehensive treatment by a physician first. In most cases, a surgical procedure is necessary for desmoid tumor. Afterwards, the affected person should in any case rest and take care of his body. Efforts or other stressful activities should be refrained from in order not to put unnecessary strain on the body. In most cases, those affected by desmoid tumors are also dependent on the help and support of friends and family. In this context, loving and intensive care also has a positive effect on the course of the disease. Even after successful removal of the desmoid tumor, regular examinations are advisable in order to detect other tumors at an early stage. Possibly, this disease also reduces the life expectancy of the affected person.

What you can do yourself

Therapy tailored to the individual patient is very important. Once treatment has been given, a largely normal life can be led. This includes regular check-ups and, if necessary, appropriate follow-up treatments. Under certain circumstances, pain may occur in connection with the disease. In this case, it is advisable to contact a local or national pain center to obtain advice on what to do in this case. At present, no concrete measures are known with which it would be possible to prevent the initial occurrence or recurrence of a desmoid tumor itself. For this reason, recommendations for self-help are largely limited to leading as normal a life as possible and, if necessary, contacting a patient organization and/or a self-help group. A good contact for those affected is the organization SOS-DESMOID. Valuable information can be obtained here. It is also possible to exchange information with other affected persons. This is very important, especially for diseases that are relatively rare. Knowing that you are not alone can do a lot of good and even make a significant contribution to improving your general well-being.