What is Phyllodes Tumor of the Breast?

The Phyllodes tumor of the breast is a rare type of fibroepithelial tumor, accounting for only 0.3% to 1% of all breast tumors. This type of tumor ranges from benign (or non-cancerous) to malignant (or cancerous), and its appearance can greatly vary (as shown in the image titled “Phyllodes Tumor of the Breast, Benign. H/E 4×”).

The World Health Organization classifies Phyllodes tumors into three groups, based on various features observed under a microscope: benign, borderline, and malignant. These features include abnormal cell growth in the nucleus, the level of cellular activity in the tissue, the appearance of the tumor edge, and an overgrowth of tissue.

Phyllodes tumors carry a risk of recurrence (coming back) or metastasis (spreading to other parts of the body), which changes depending on the aforementioned features. The diagnosis of these tumors primarily relies on microscopic examination of the tissue. However, it can be challenging to distinguish between a benign phyllodes tumor and another non-cancerous breast condition called fibroadenoma, particularly when examining small tissue samples obtained through a core biopsy.

What Causes Phyllodes Tumor of the Breast?

Scientists don’t know much about the genes responsible for phyllodes tumors, but they have found these types of tumors in patients with Li-Fraumeni syndrome (a rare, inherited disorder that greatly increases the risk of developing several types of cancer) and in a mother-daughter pair. Cases of phyllodes tumors in men are rare but often related to gynecomastia, a condition that swells the breast tissue in boys or men, suggesting that a hormone imbalance may play a role.

Research suggests these tumors could be caused by growth factors produced by the cells covering the mammary glands (breasts). We don’t fully understand this process just yet, but something called endothelin-1, which boosts the growth of the connective tissue cells in the breast, might play a role.

While more research is needed, some factors like physical trauma, pregnancy, increased estrogen activity, and breastfeeding are occasionally thought to encourage these tumors to grow.

Risk Factors and Frequency for Phyllodes Tumor of the Breast

Phyllodes tumors are usually found in middle-aged women, typically around 40 to 50 years old. This is generally 15 to 20 years later than when similar growths, known as fibroadenomas, occur. Although these tumors primarily occur in women, there have been some cases reported in men. According to data from the Surveillance, Epidemiology, and End Results Program, it’s estimated that each year in the US, around 500 women are diagnosed with malignant, or harmful, phyllodes tumors.

Signs and Symptoms of Phyllodes Tumor of the Breast

Phyllodes tumors are often identified as hard, painless lumps in one breast that grow rapidly and can stretch the skin, causing the veins on the surface to look prominent. These tumors can range in size from 1 to 45 cm, sometimes filling the entire breast. Occasionally, there may be a bloody discharge from the nipple due to the tumor breaking down. Uncommon symptoms include the forming of ulcers or the nipple being pulled inwards. Swollen lymph nodes in the armpit are often present, but it is rare for these tumors to spread to the lymph nodes.

Testing for Phyllodes Tumor of the Breast

In a mammogram, a Phyllodes tumor typically shows up as a round, dense lump with edges that may be somewhat unclear or distinct. It’s unusual for these types of masses to have calcifications – hardened deposits -, but it can occasionally happen, and they can be quite large.

An ultrasound can also help provide more information about Phyllodes tumors. In these scans, the tumor usually appears as a somewhat unclear, light-gray mass. It often shows an increase in brightness behind the mass, a phenomenon called “posterior enhancement.” Malignant Phyllodes tumors, which are more aggressive, may display a cystic component, an area that appears like a fluid-filled sac.

Colored ultrasound scans can help us see the increased blood flow in and around these tumors – something often seen in Phyllodes tumors.

Magnetic resonance imaging (MRI) is useful to determine whether a malignant Phyllodes tumor has spread to the chest wall – a part of the body that includes the bones and muscles that protect the heart and lungs. On an MRI, these tumors appear as uneven areas of low signal intensity on T1-weighted scans, although there could be brighter areas indicating internal bleeding. T2-weighted scans usually show the lumpy mass with bright areas representing fluid and sometimes brighter areas in nearby tissues.

Treatment Options for Phyllodes Tumor of the Breast

If you have a small tumour, having surgery to remove the tumour and some of the surrounding tissue, often referred to as “wide local excision,” can often cure the condition and make it less likely the tumour will return. If the tumour is large, you may require a mastectomy, which is the removal of the entire breast.

It’s important to note, that while saving as much of the breast as possible may lead to a higher chance of the tumour coming back in the same place, studies have shown that whether you have a mastectomy or a less invasive surgery, does not affect the chances of the cancer spreading elsewhere in the body or your overall survival rate.

Your doctor might also suggest radiation therapy. This is a kind of treatment that uses high-energy rays (like X-rays) to kill cancer cells, and it’s been shown to make it less likely for the tumour to return. However, studies have yet not proven any benefits of chemotherapy, a treatment that uses drugs to attack cancer cells, as an additional treatment option after surgery.

When a patient has a phyllodes tumor in the breast, doctors must consider other conditions that have similar symptoms. These include:

  • Fibroadenoma: This condition is very similar to a benign phyllodes tumor.
  • Sarcomas: Malignant phyllodes tumor can sometimes be confused with other types of breast sarcomas.
  • Periductal stromal tumor: This kind of tumor is quite similar to malignant phyllodes tumor, but it doesn’t have the so-called “leaf-like” features and it’s localized around open tubules.
  • Metaplastic carcinoma: This type of cancer is also considered when diagnosing malignant phyllodes tumor, but certain tests (immunohistochemical demonstration) can help doctors differentiate between the two conditions.

Without careful medical examination and tests, these conditions can be easily confused.

What to expect with Phyllodes Tumor of the Breast

The outlook for patients with a type of tumor called Phyllodes is generally good. Statistics show that about 87% of patients live for at least 10 years after diagnosis. However, the chance of the tumor coming back can depend on how big the tumor is and what type of surgery was used to remove it.

Most of the time, Phyllodes tumors are not harmful and only return in a small number of cases. Although it is very rare, there are occasions where the tumor can spread to other parts of the body, especially if the tumor is considered malignant or harmful. If the Phyllodes tumor is malignant, the outlook isn’t as good.

Possible Complications When Diagnosed with Phyllodes Tumor of the Breast

Phyllodes tumors can sometimes come back locally, regardless of whether they’re benign or malignant. The overall recurrence rate is about 21%. The chance of recurrence for benign phyllodes tumors is around 10% to 17%. For borderline malignant tumors, the rate is roughly 14% to 25%. For fully malignant phyllodes tumors, recurrence can happen in about 23% to 30% of cases. Any recurrence usually happens within the first 2 to 3 years.

  • Overall recurrence rate: 21%
  • Benign phyllodes tumors recurrence: 10% to 17%
  • Borderline malignant tumors recurrence: 14% to 25%
  • Malignant phyllodes tumors recurrence: 23% to 30%

On the other hand, phyllodes tumors can also spread to distant parts of the body. This is called metastasis, and it’s generally only a feature of malignant tumors. The lungs, bones, and brain are the most common places for these tumors to spread, with rates of 66%, 28%, and 9% respectively. On rare occasions, tumors can even spread to the liver and heart.

  • Lung metastasis: 66%
  • Bone metastasis: 28%
  • Brain metastasis: 9%
  • Liver and heart metastasis: Rare

Preventing Phyllodes Tumor of the Breast

Patients may be advised to regularly check their own breasts for any changes or oddities. If they notice anything unusual, it is important that they reach out to their doctor for a consultation. This helps catch any potential issues early and begin treatment promptly, if necessary.

Frequently asked questions

The prognosis for Phyllodes Tumor of the Breast is generally good, with about 87% of patients living for at least 10 years after diagnosis. However, the chance of the tumor coming back can depend on the size of the tumor and the type of surgery used to remove it. In rare cases, the tumor can spread to other parts of the body, especially if it is considered malignant.

Factors such as physical trauma, pregnancy, increased estrogen activity, and breastfeeding are occasionally thought to encourage the growth of Phyllodes tumors of the breast.

Signs and symptoms of Phyllodes Tumor of the Breast include: - Hard, painless lumps in one breast - Rapid growth of the tumor - Stretching of the skin, causing prominent veins on the surface - Size of the tumor can range from 1 to 45 cm, sometimes filling the entire breast - Occasionally, there may be a bloody discharge from the nipple due to the tumor breaking down - Uncommon symptoms include the forming of ulcers - The nipple may be pulled inwards - Swollen lymph nodes in the armpit are often present - It is rare for these tumors to spread to the lymph nodes.

The types of tests that are needed for Phyllodes Tumor of the Breast include: - Mammogram: to detect the presence of a round, dense lump with unclear or distinct edges - Ultrasound: to provide more information about the tumor, such as its appearance as a light-gray mass with posterior enhancement and possible cystic component - Colored ultrasound: to visualize increased blood flow in and around the tumor - Magnetic resonance imaging (MRI): to determine if the tumor has spread to the chest wall, with T1-weighted scans showing areas of low signal intensity and possible internal bleeding, and T2-weighted scans showing the lumpy mass with bright areas representing fluid and sometimes brighter areas in nearby tissues.

The other conditions that a doctor needs to rule out when diagnosing Phyllodes Tumor of the Breast are: - Fibroadenoma - Sarcomas - Periductal stromal tumor - Metaplastic carcinoma

The side effects when treating Phyllodes Tumor of the Breast may include: - Possibility of recurrence: - Overall recurrence rate: 21% - Benign phyllodes tumors recurrence: 10% to 17% - Borderline malignant tumors recurrence: 14% to 25% - Malignant phyllodes tumors recurrence: 23% to 30% - Recurrence usually happens within the first 2 to 3 years. - Possibility of metastasis: - Lung metastasis: 66% - Bone metastasis: 28% - Brain metastasis: 9% - Rare cases of metastasis to the liver and heart.

You should see an oncologist or a breast surgeon for Phyllodes Tumor of the Breast.

It is estimated that each year in the US, around 500 women are diagnosed with malignant, or harmful, phyllodes tumors.

Phyllodes Tumor of the Breast can be treated through surgery, specifically a wide local excision for small tumors or a mastectomy for larger tumors. Radiation therapy may also be recommended to reduce the likelihood of the tumor returning. However, there is no proven benefit of chemotherapy as an additional treatment option after surgery.

The Phyllodes tumor of the breast is a rare type of fibroepithelial tumor that can range from benign to malignant. It accounts for only 0.3% to 1% of all breast tumors.

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