1. What is a borderline or malignant phyllodes tumour?
2. What are the symptoms of a phyllodes tumour?
3. How is a borderline or malignant phyllodes tumour diagnosed?
4. How is a borderline or malignant phyllodes tumour treated?
5. Coping with a borderline or malignant phyllodes tumour

1. What is a borderline or malignant phyllodes tumour?

A phyllodes tumour is a hard lump of tissue that develops from the stroma (supportive tissue) of the breast.

There are three types of phyllodes tumours:

  • benign (not cancer)
  • borderline (these have most of the same features as a benign phyllodes tumour but also have some abnormal characteristics)
  • malignant (cancer)

They are grouped according to how they look under a microscope. Pathologists (doctors who examine tissue from a biopsy or surgery) decide this by looking at a number of things. For example, how quickly the cells are dividing, how abnormal the cells are and whether they are growing into the surrounding breast tissue.

Borderline and malignant phyllodes tumours are rare. They account for less than 1% of breast cancers.

Phyllodes tumours are most common in women between 40 and 50 who haven’t yet been through the menopause, although they can occur at any age. Phyllodes tumours can also occur in men, although this is very rare.

The outlook (prognosis) for borderline and malignant phyllodes tumours is very good.

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2. What are the symptoms of a phyllodes tumour?

Symptoms of phyllodes tumours can include:

  • a smooth, hard lump
  • sometimes seen as a smooth bulge under the skin
  • occasionally fast-growing and becoming quite large

Routine breast screening can often pick up changes in the breast before a woman notices any symptoms. Therefore some women who attend breast screening may be referred for further tests and are diagnosed with a phyllodes tumour without having any symptoms.

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3. How is a borderline or malignant phyllodes tumour diagnosed?

Phyllodes tumours are diagnosed using a range of tests, which may include:

In some situations a fine needle aspiration (FNA) may be done, but this is not commonly used in testing for phyllodes tumours. An FNA uses a fine needle and syringe to take a sample of cells.

Your specialist may also suggest you have a magnetic resonance imaging (MRI) scan. This uses magnetic fields and radio waves to produce a series of images of the inside of the breast.

Phyllodes tumours are often difficult to diagnose because they can be confused with other breast problems, particularly a benign breast condition called a fibroadenoma. This means your specialist team may  not be sure of the diagnosis until the whole tumour is removed and examined by a pathologist.

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4. How is a borderline or malignant phyllodes tumour treated?


Surgery is usually the main treatment recommended for borderline or malignant phyllodes tumour. 

You may be offered breast-conserving surgery or a mastectomy. Your specialist will discuss with you what type of surgery you need.

If you have breast-conserving surgery, it’s important to have a clear margin of normal breast tissue when the lump is removed to reduce the risk of the tumour coming back (known as local recurrence). If there isn’t a clear margin then more surgery is usually recommended.

Unlike other types of breast cancer, borderline or malignant phyllodes tumours rarely spread to the lymph nodes (glands) under the arm (axilla), so these will not be removed routinely during surgery. However, your surgeon will look at your individual case and recommend the best surgery for you.

If you are going to have a mastectomy, you will usually be able to have breast reconstruction. This can be done at the same time as your mastectomy (immediate reconstruction) or months or years later (delayed reconstruction).

If you are unable to have breast reconstruction, choose not to or have a delayed reconstruction, you may want to read about breast prostheses, bras and clothes after surgery. The choice of whether or not to have a reconstruction or wear a prosthesis is very personal and some women choose not to have a reconstruction and choose not to wear a prothesis.

Are there any adjuvant (additional) treatments after surgery?

Some people with breast cancer are given further treatments (such as chemotherapy, radiotherapy or hormone therapy) to reduce the risk of the cancer coming back. These are known as adjuvant (additional) treatments.

It’s unlikely you’ll need any additional treatments after surgery, even if you have a malignant phyllodes tumour.

In very rare situations you may be offered radiotherapy or chemotherapy. In this case it will be recommended that you see an oncologist (a doctor who specialises in the treatment of cancer) to discuss your situation.

Your specialist team will be able to tell you if there are any clinical trials that you could take part in.

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5. Coping with a borderline or malignant phyllodes tumour

Being told you have a borderline or malignant phyllodes tumour can be a very anxious, frightening and isolating time. Having a rarer type of breast cancer may add to your anxiety. However, there are people who can support you, so don’t be afraid to ask for help if you need it. Let other people know how you are feeling, particularly family and friends so they can be more supportive.

Some people find it helpful to discuss their feelings and concerns with their breast care nurse or specialist. If you feel you’d like to talk through your feelings and concerns in more depth over time, a counsellor or psychologist may be more appropriate. Your breast care nurse, specialist or GP (local doctor) can arrange this.

If you want to talk you can also call our Helpline on 0808 800 6000.

Find out more about how Breast Cancer Care can support you.

Last reviewed: August 2017
Next planned review begins 2019

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