Desmoid Tumours

Desmoid tumours, also known as aggressive fibromatosis or musculoaponeurotic fibromatosis, are rare tumours that develop from connective (or fibrous) tissue in the body. These tumours are generally benign, however they can be aggressive and behave like a cancer.

The body is primarily composed of four main tissue types: muscular, nervous, epithelial, and connective. Muscular tissue is made up of thin and elongated cells (known as muscle fibres), and is responsible for the voluntary and involuntary movement of an organism. Nerve tissue consists of two cell types (neurons and glial cells), and is responsible for the coordination and regulation of many bodily functions. Epithelial tissue forms a covering of all bodily surfaces, line body cavities and hollow organs, and make up majority of gland tissue. It has a variety of functions, including protection, secretion, and absorption of substances. Connective tissue, such as fat (adipose tissue), cartilage, bone, and blood, are responsible for connecting, separating, and supporting all other types of tissues in the body.

As connective tissue is found everywhere in the body, desmoid tumours can develop just about anywhere. However, it is most commonly found in the arms, legs, and abdomen.

Desmoid tumours are more common in females, and are generally diagnosed in people between the ages of 15-40. However, anyone can develop this disease.

Types of Desmoid Tumours

There are three primary types of desmoid tumours, which are categorised by the area of the body they originate from.

Extra-abdominal Desmoid Tumours

Extra-abdominal desmoid tumours are found outside of the abdomen, most commonly in the arms, legs, chest wall or the head and neck region.  In rare cases, they can also be found in the bladder or scrotum.

Abdominal Desmoid Tumours

Abdominal desmoid tumours, also known as abdominal wall desmoid tumours, are found within the abdominal wall. The abdominal wall surrounds the abdominal cavity, providing coverage and protection of the organs within this region from damage.

Intra-abdominal Desmoid Tumours

Intra-abdominal desmoid tumours are tumours that develop from the tissue connecting abdominal organs. This can include the mesentery, which is the tissue that provides blood vessels and padding to the intestines.

Treatment

When cancers are detected, they are staged and graded based on size, metastasis, and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you. However, because of how rare desmoid tumours are, there is currently no standard staging and grading system for this disease. Instead of staging and grading, your doctor will recommend a treatment plan based on the following factors:

  • Tumour location.
  • Your age.
  • General health.
  • Your treatment preferences.

Your doctor may also recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.

Treatment options for desmoid tumours may include:

  • Watch and wait.
  • Surgery to remove as much of the tumour as possible.
  • Radiation therapy.
  • Chemotherapy.
  • Anti-inflammatory medication, potentially including non-steroidal anti-inflammatory drugs (NSAIDs) and Imatinib.
  • Hormone therapy.
  • Targeted therapy.
  • Clinical trials.
  • Palliative care.

Risk Factors

While the cause of desmoid tumours remain unknown, the following factors may increase the likelihood of developing the disease:

  • Having familial adenomatous polyposis (FAP).
  • Pregnancy (rare).
  • Genetic mutation of the adenomatous polyposis coli (APC) gene.
  • Severe and/or repeated trauma to the body.
  • High levels of the hormone oestrogen.

Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.

Symptoms

The symptoms of a desmoid tumour will often vary based on location. In general, the symptoms of a desmoid tumour may include:

  • A mass in the affected area.
  • Swelling of affected area.
  • Pain or soreness, potentially caused by compressed nerves, blood vessels, and/or muscles.
  • Loss of function of affected area.
  • Nausea and/or vomiting.
  • Abdominal cramping (when tumour is in the abdomen).
  • Bowel obstruction (commonly for intra-abdominal tumours), which may cause:
    • Bloating.
    • Constipation.
    • Abdominal pain.
    • Ruptured intestines.
  • Limping or other difficulties using the legs and feet (if tumour is located on the legs).
  • Tingling in affected area, often caused by the tumour compressing nearby nerves and/or blood vessels.

Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.

Diagnosis

If your doctor suspects you have a desmoid tumour, they may order the following tests to confirm the diagnosis and refer you to a specialist for treatment:

  • Physical examination.
  • Imaging tests, potentially including:
    • MRI (magnetic resonance imaging).
    • CT (computed tomography) scan.
  • Biopsy.

References

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