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

• BPNST of Breast
• Mammary Benign Peripheral Nerve Sheath Tumors
• Mammary BPNST

What is Benign Peripheral Nerve Sheath Tumors of Breast? (Definition/Background Information)

• Benign Peripheral Nerve Sheath Tumors of Breast are a group of benign tumors affecting the soft tissues or peripheral nerves (nerve sheath) in the breast. These tumors are very rare and are known to occur in young and old individuals (mostly women)
• Generally, Benign Peripheral Nerve Sheath Tumors (BPNSTs) are of 3 distinct types:
  • Schwannoma: Schwannomas are benign tumors that arise from the Schwann cells around the nerves; these tumors are nerve sheath tumors. In a majority of cases, these tumors are solitary
  • Perineurioma: Perineurioma is a rare tumor of the perineurial cells, a type of cells that are present around a peripheral nerve sheath
  • Neurofibroma: Neurofibroma is a skin outgrowth that consists of Schwann cells, perineurial cells, and fibroblasts (type of connective tissue cells)
• Of the 3 types, only Schwannomas and Neurofibromas have been recorded as affecting the breast. Primary Perineurioma tumors affecting the breast is not known to occur
  • Currently, no causative factors have been identified for Schwannoma of Breast. The risk factors for the tumor include the presence of neurofibromatosis type 2 (NF2) and a positive family history of Schwannoma
  • Neurofibroma of Breast may occur against a background of neurofibromatosis type 1 (NF1), which is a multisystem genetic disorder affecting the nervous system, skin, and skeletal muscles
• The signs and symptoms of Benign Peripheral Nerve Sheath Tumors of Breast may include the presence of a lump in the breast. Small-sized tumors may be asymptomatic and show no signs and symptoms
• Both Schwannomas and Neurofibromas of the Breast are treated through surgery, per the healthcare provider’s recommendation. The prognosis is good with its complete removal, since these are benign tumors
• Nevertheless, it also depends on the presence of any underlying conditions (such as NF1 or NF2). Hence, periodic checkups and screening mammograms are advised

Who gets Benign Peripheral Nerve Sheath Tumors of Breast? (Age and Sex Distribution)

• Benign Peripheral Nerve Sheath Tumors of Breast are rare tumors of the breast and very few cases have been recorded in the medical literature. The age of presentation of these tumors range from 15-80 years
  • Schwannomas, in general, are mostly observed between the age ranges of 20-50 years. It is observed in young and middle-aged adults
  • Neurofibromas, not associated with neurofibromatosis type 1, usually occur in individuals, who are in their 60s. If associated with NF1, they are observed in individuals at a much younger age (less than 60 years)
• All racial and ethnic groups are affected and no specific predilection is seen

What are the Risk Factors for Benign Peripheral Nerve Sheath Tumors of Breast? (Predisposing Factors)

The specific risk factors for Benign Peripheral Nerve Sheath Tumors of Breast may include:

• The presence of neurofibromatosis type 2, a genetic condition that is characterized by the formation of non-cancerous tumors that affect the nervous system
• The presence of neurofibromatosis type 1, a genetic condition that is characterized by skin pigmentation and the formation of non-cancerous tumors that affect the central nervous system
• Gender: Women have a higher risk for developing the condition than men

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones 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 Benign Peripheral Nerve Sheath Tumors of Breast? (Etiology)

• The exact cause of development of Benign Peripheral Nerve Sheath Tumors of Breast is currently not clearly understood
• Certain gene mutations have also been reported in the tumors. Research is being performed to determine how these mutations contribute to the formation of the tumors

What are the Signs and Symptoms of Benign Peripheral Nerve Sheath Tumors of Breast?

The signs and symptoms of Benign Peripheral Nerve Sheath Tumors of Breast may include:

• A benign lump in a single breast; typically, only one breast is affected
• The tumors can appear as firm, painless nodules
• Larger tumors may be felt by touch; small tumors may be missed during a mammogram screening
• The signs and symptoms of neurofibromatosis (type 1 or 2) may be present

How is Benign Peripheral Nerve Sheath Tumors of Breast Diagnosed?

Benign Peripheral Nerve Sheath Tumors 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. These benign tumors are identified as a mammogram mass, which may or may not be associated with microcalcification. The mammography findings may raise enough suspicion to warrant a tissue biopsy
• Breast ultrasound scan: Using high-frequency sound waves to produce images of the breast, the type of tumor, whether fluid-filled cyst or solid mass type, may be identified
• Computerized tomography (CT) or magnetic resonance imaging (MRI) scan of the breast
• 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. FNAB cannot help definitively diagnose Benign Peripheral Nerve Sheath Tumors of Breast. It only helps determine if the tumor is malignant or benign. This can help the healthcare provider discuss and plan the next steps (with respect to diagnosis and treatment)
• 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 Benign Peripheral Nerve Sheath Tumors of Breast?

The complications of Benign Peripheral Nerve Sheath Tumors of Breast may include the following:

• Breast cancer is known to occur against a background of neurofibromatosis types 1 or 2
• Complications may occur from the underlying conditions (NF1 or NF2), if any

How is Benign Peripheral Nerve Sheath Tumors of Breast Treated?

The following treatment methods for Benign Peripheral Nerve Sheath Tumors of Breast may be considered:

• A ‘wait and watch’ approach may be considered for asymptomatic tumors that are not observed to be associated with neurofibromatosis
• A simple surgical excision and removal of the entire tumor is the treatment of choice, when the individual is affected by neurofibromatosis or if the tumor causes significant signs and symptoms
  • The surgical procedure performed is known as a breast lumpectomy. It is a surgical procedure to remove the breast lump, which may be done under a general anesthetic
  • During the surgery, a small incision is made in the skin of the breast and a hollow probe that is connected to a vacuum, inserted
  • The breast tissue is sucked through the probe, using vacuum, until the lump has been removed
• Follow-up care with frequent breast self-examinations and screening mammograms may be recommended by the healthcare provider

How can Benign Peripheral Nerve Sheath Tumors of Breast be Prevented?

The development of Benign Peripheral Nerve Sheath Tumors of Breast is difficult to prevent. Currently, no specific preventive measures are available to avoid BPNST of Breast.

In general, however, it is important to be aware of certain risk factors for breast tumors.

• The individual must regularly conduct breast self-exams, to ensure that no lumps are present
• Maintain a healthy body weight and exercise regularly
• Implement and follow a well-balanced diet; a high intake of fiber via fresh fruits and vegetables helps in a healthy lifestyle
• Avoid or completely stop smoking
• Drink alcohol in moderation; limit to one or (maximum) two drinks a day
• Limit combination hormone therapy used to treat symptoms of menopause. It is advised that individuals be aware of the potential benefits and risks of hormone therapy

What is the Prognosis of Benign Peripheral Nerve Sheath Tumors of Breast? (Outcomes/Resolutions)

• The prognosis of Benign Peripheral Nerve Sheath Tumors of Breast is generally excellent on a surgical excision and removal of the tumor
• Nevertheless, Benign Peripheral Nerve Sheath Tumors of Breast is associated with an increased risk for breast cancer into the future, when it is associated with either neurofibromatosis type 1 or neurofibromatosis type 2
• Therefore, periodic follow-up check-ups with screening is required

Additional and Relevant Useful Information Benign Peripheral Nerve Sheath Tumors of Breast:

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

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

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