What are the other Names for this Condition? (Also known as/Synonyms)

• Aggressive Fibromatosis of Breast
• Desmoid Tumor of Breast
• Mammary Musculoaponeurotic Fibromatosis

What is Desmoid Fibromatosis of Breast? (Definition/Background Information)

• Desmoid fibromatosis, or desmoid tumor, is benign tumor of the connective tissues of the body. Even though benign, the tumor displays local aggression and can invade uncontrollably into the surrounding tissues and structures. In many cases, the tumor involves the abdomen region
• Desmoid Fibromatosis of Breast is an uncommon site for this tumor. The tumor can arise from the breast tissues, in which case it is called Primary Mammary Fibromatosis; or form in the chest wall and invade into the breast
• This can result in an associated set of signs and symptoms including pain, discomfort, and rarely, nipple discharge. Desmoid Fibromatosis of Breast is diagnosed on a breast biopsy by a pathologist when examined under the microscope
• The cause of Desmoid Fibromatosis of Breast is generally unknown, but contributory factors that relate to genetic abnormalities and physical trauma are noted. Individuals with the genetic condition familial adenomatous polyposis (FAP) may also present desmoid fibromatosis tumors
• Desmoid Fibromatosis of Breast is usually treated through surgical excision, per the healthcare provider’s recommendation. Due to the infiltrative nature of the tumor, in many cases, it may be only possible to remove the tumor partially. The prognosis is generally good for small-sized tumors that are detected early and removed via surgery

Who gets Desmoid Fibromatosis of Breast? (Age and Sex Distribution)

• Desmoid Fibromatosis of Breast is rare and constitute less than 2% of all tumors of the breast
• A vast majority of cases are observed in young and middle-aged women. Most cases are seen in the age group of 20-50 years, although individuals of any age may be affected
• The condition can affect individuals of all races and ethnic backgrounds

What are the Risk Factors for Desmoid Fibromatosis of Breast? (Predisposing Factors)

No specific risk factors have been identified for Desmoid Fibromatosis of Breast.

• Genetic factors: Some tumors are known to be associated with familial adenomatous polyposis (FAP); less than 10% of the cases are seen with FAP
• Physical factors: Some studies show that these desmoid fibromatosis tumors are associated with trauma due to surgery (noted in over 44% of the cases)
• Breast implants that are saline or silicone based
• Sporadic tumors, which do not occur against a background of any associated genetic disorders, are more commonly noted and form the vast majority of cases (over 90% of the cases)

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Desmoid Fibromatosis of Breast? (Etiology)

The exact cause of development of Desmoid Fibromatosis of Breast is presently not clearly understood.

• 83-95% of the tumors occurring with no attributed cause (or sporadic tumors) show genetic mutations on the CTNNB1 gene. The significance of the role of tumor development due to genetic abnormalities is not clearly understood
• The remaining sporadically occurring tumors reportedly show APC gene inactivation
• Desmoid fibromatosis tumors associated with familial adenomatous polyposis are also known to display APC gene mutations

What are the Signs and Symptoms of Desmoid Fibromatosis of Breast?

The signs and symptoms of Desmoid Fibromatosis of Breast may include:

• Presence of a poorly-defined tumor mass that involves the breast tissues; in some, an involvement of the superficial skin layers may be noted
• The size may vary from 1 to 10 cm or more; some tumors are less than 1 cm in size
• The tumors grow slowly, are non-tender, and firm to touch
• Occasionally, nipple discharge, pain in the region, and retraction of skin may be observed
• Large-sized desmoid fibromatosis tumors are generally painful
• The tumor may grow to involve the soft tissues of the axilla (near the underarms), which may be mistaken for lymph node swelling
• Most tumors are solitary and display aggressive invasion to nearby tissues and structures

How is Desmoid Fibromatosis of Breast Diagnosed?

Desmoid Fibromatosis of Breast may be diagnosed in the following manner:

• Complete physical examination with comprehensive medical and family history evaluation
• Breast exam to check for any lumps or unusual signs in the breasts
• Mammogram: A mammogram uses X-rays to provide images of the breast
• Breast ultrasound scan: Using high-frequency sound waves to produce images of the breast
• Computerized tomography (CT) or magnetic resonance imaging (MRI) scan of the breast
• Molecular genetic studies, if available
• Breast biopsy:
  • A biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
  • Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
  • Sometimes, the pathologist may perform additional studies, which may include immunohistochemical stains and molecular studies to assist in the diagnosis

Biopsies are the only methods used to determine whether an abnormality is benign or cancerous. These are performed by inserting a needle into a breast mass and removing cells or tissues, for further examination. There are different types of biopsies:

• Fine needle aspiration biopsy (FNAB) of breast mass: In this method, a very thin needle is used to remove a small amount of tissue
• Core needle biopsy of breast mass: A wider needle is used to withdraw a small cylinder of tissue from an abnormal area of the breast
• Open tissue biopsy of breast mass: A surgical procedure used less often than needle biopsies, it is used to remove a part or all of a breast lump for analysis

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Desmoid Fibromatosis of Breast?

The complications of Desmoid Fibromatosis of Breast may include:

• It can cause emotional stress due to concerns of a malignancy
• Severely infiltrating and aggressive tumors can destroy the surrounding tissues and organs and cause their functional impairment
• Risk of local recurrence following surgery is moderately high (between 25-29%)
• Complications may arise from the underlying genetic syndrome, if any present

How is Desmoid Fibromatosis of Breast Treated?

The following treatment methods may be considered for Desmoid Fibromatosis of Breast:

• Wait and watch approach for tumors that are small, presenting no pain, or other significant signs and symptoms
• Symptomatic treatment through pain and anti-inflammatory medication, as needed
• Use of non-steroidal anti-inflammatory drugs (NSAIDs) is found to be beneficial in some cases of desmoid fibromatosis, prior to surgery
• Surgical excision and removal of the entire tumor is normally recommended due to its aggressive and invasive nature. However, it is difficult to remove the tumor entirely due to its infiltration into the surrounding tissues. In many cases, multiple surgeries may be required to completely remove the desmoid fibromatosis tumors
• Radiation therapy: Using high-energy beams, including X-rays, to destroy the tumor
• Chemotherapy: Using the help of medicines to kill tumor cells or shrink the tumor size
• Hormone therapy drugs may be used to control the growth of tumor cells
• Targeted therapy: Targeted therapy drugs attack the tumor cells in a specific manner
• Undertaking treatment of the underlying familial adenomatous polyposis if present

Follow-up care with regular breast self-examinations and screening mammograms are important and may be recommended by the healthcare provider.

Many experts believe that the tumor has a persistent growth pattern, and many women have been recommended to have the tumor excised. Recently it has been observed that women who have chosen not to undergo surgery for removing the tumor, the tumor stops growing in size after a while. This observation has prompted many healthcare experts to believe that a “wait and watch” approach should be preferred to immediate surgery. Such a decision is made on a thorough evaluation of the tumor size, its growth pattern, and the individual’s personal preferences. Many individuals choose to undergo surgical excision to rule out the possibility of a breast cancer.

How can Desmoid Fibromatosis of Breast be Prevented?

Currently, no specific preventive measures are available to prevent the occurrence of Desmoid Fibromatosis of Breast.

What is the Prognosis of Desmoid Fibromatosis of Breast? (Outcomes/Resolutions)

Desmoid Fibromatosis of Breast is a locally aggressive tumor that is known to infiltrate and destroy the surrounding tissue structures, even though it is designated as benign. The prognosis may be good with adequate treatment (surgery).

• Local recurrence is commonly noted, but studies point to an incomplete excision and removal of the tumor. Due to infiltrative nature, it is also very difficult to achieve clear and wide margins for a complete surgical excision
• Desmoid fibromatosis occurring against a background of familial adenomatous polyposis may have poorer outcomes
• The tumor is not known to undergo malignant transformations; and according to reports, there is no potential for metastasis

However, individuals who have undergone radiation therapy to the breast, may develop a condition called irradiated fibromatosis, which needs to be closely watched. This is due to the fact that radiation-induced sarcoma (a malignant tumor) and irradiated fibromatosis may be biologically related to each other

Additional and Relevant Useful Information for Desmoid Fibromatosis of Breast:

The following DoveMed website links are useful resources for additional information:

https://www.dovemed.com/healthy-living/womens-health/

https://www.dovemed.com/diseases-conditions/cancer/