Phyllodes Tumors of the Breast: Everything You Need to Know

Medically Reviewed by Emmanuel M. Gabriel, MD, PhD
Written by Vanessa LeongJan 2, 20245 min read
Breast Examination

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What are phyllodes tumors of the breast?

It's not easy to hear about any kind of breast tumor, and Phyllodes tumors are no exception. While they are quite rare, these breast tumors may develop in the breast's connective tissue. The good news is that the majority of these tumors (about 75%) are benign. However, in some cases, they can become cancerous. It's important to keep in mind that phyllodes tumors account for less than 1% of all breast tumors. If you or someone you know has been diagnosed with this type of tumor, it's important to seek guidance from a medical professional and follow their recommendations for treatment.

Sometimes, a phyllodes tumor may be misidentified as a fibroadenoma, which is a non-cancerous breast lump, and vice versa. Distinguishing between phyllodes tumors and fibroadenomas can be difficult, particularly in imaging or core biopsy specimens. This can lead to misdiagnosis, which can be worrisome. Although phyllodes tumors can occur at any age, women in their 40s may be at a higher risk. Additionally, those with Li-Fraumeni syndrome may also have an increased risk of developing phyllodes tumors.

Phyllodes tumors can be grouped into 3 categories:

  • Benign

These are non-cancerous tumors characterized by slower growth and are least likely to spread. They account for more than 50% of all phyllode tumors.

  • Borderline

These have both cancerous and non-cancerous characteristics and account for approximately 25% of all phyllode tumors.

  • Malignant

These are cancerous tumors that tend to grow the fastest and are the most likely to spread or recur after treatment. They account for about 25% of all phyllode tumors.

Symptoms

The most common symptom of a phyllodes tumor is a firm lump in the breast, which may or may not be painful. They tend to grow rapidly, often causing the skin to stretch.

Diagnosis

Phyllodes tumors are usually detected through imaging tests like mammography or breast ultrasounds. A core needle biopsy is often needed to diagnose phyllodes tumors as they cannot be distinguished through imaging tests alone. Due to its similarity to fibroadenomas and the difficulty of differentiating them in needle core biopsies, an excisional biopsy may sometimes be required. Unlike needle core biopsies, which only remove a small piece of tumor tissue, excisional biopsies remove the entire tumor.

Treatment

Excisional biopsy

Benign tumors may be treated with just an excisional biopsy if the whole tumor was properly and completely removed.

Lumpectomy

A lumpectomy may be recommended for borderline and malignant tumors as a larger area of healthy breast tissue around the tumor (called a margin) needs to be removed along with the tumor.

Mastectomy

If a margin cannot be removed with a lumpectomy, a mastectomy may be required instead.

Radiation therapy

Radiation therapy may be given after surgery to ensure that all tumor cells are gotten rid of.

Chemotherapy and hormone therapy is generally not used to treat phyllodes tumors as they do not respond in the same way to these treatments as other more typical types of breast cancer.

Prognosis

Generally, the prognosis for this specific type of breast tumor is positive, with a low recurrence rate of around 8%. However, there is a possibility that some tumor cells may remain even after surgery, and recurrence of phyllodes tumor may occur several years later. To stay on top of any potential recurrence, it is advisable to have regular mammograms or ultrasounds.

Rest assured that a medical professional will be there every step of the way to address any concerns.

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This article has been medically reviewed and fact-checked to ensure our content is informed by the latest research in cancer, global and nationwide guidelines and clinical practice.

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