Phyllodes tumours are a rare type of breast lump. They can be non-cancerous (benign) or cancerous. But, most are benign and can be cured with an operation.

The first sign is usually a fast growing lump in the breast. People of any age can be affected but they are most often found in women between the ages of 40 and 50. Phyllodes tumours are more common in women who have or have had benign lumps in the breast, called fibroadenomas. But, it isn’t known what causes them.

Phyllodes tumours are usually diagnosed at a breast clinic using a combination of tests called a triple assessment. These include:

• A breast examination by a breast specialist
• Imaging tests such as a mammogram or ultrasound scan
• A biopsy - a sample of tissue taken from the breast lump.

A doctor looks at the tissue from the biopsy under the microscope. This shows the type of cells that make up the lump. Phyllodes tumours are made up of a mixture of cells from connective (fibrous) tissue and from the tissue layer (epithelia) that lines the breast.

Because phyllodes tumours can be benign or cancerous the doctor will also grade the cells according to how different they are from normal cells. When cells look quite normal this usually means that the tumour is benign. Very abnormal looking cells are a sign of cancer. Phyllodes tumours can be graded as benign, borderline or cancerous (malignant). Benign tumours usually stay in the area where they first appear but cancerous tumours may spread if they aren't treated.

The main treatment is an operation to remove all of the lump with a margin of healthy tissue around it. This can cure most phyllodes tumours. The surgeon will want to take away all of the lump. This is because if any tumour cells are left behind the lump can grow back.

Most women will have an operation called a wide local excision. But, if the lump is large especially if the breast is small, a mastectomy may be necessary. An operation to reconstruct the breast may be done at the same time. The lymph nodes in the armpit aren’t operated on as cells from phyllodes tumours don't usually spread to lymph nodes.

Normally no further treatment is given after surgery to remove the lump. But, doctors are interested in finding other treatments that might help to reduce the chance of the tumour growing back. A study in the US is looking into whether giving radiotherapy after breast surgery is helpful.

After surgery a woman will have regular mammograms or ultrasounds as well as check ups (often yearly) with a breast specialist. It is also important for the woman be 'breast aware' and contact the doctor if any new lumps appear. If the tumour comes back in the breast it can usually be cured with a second operation.

Occasionally cancerous phyllodes tumours can spread to other parts of the body through the bloodstream. This is called metastatic or secondary cancer. In this situation radiotherapy or chemotherapy may be used. If chemotherapy is given it may be with drugs such as doxorubicin and ifosfamide. It is similar to chemotherapy used to treat a type of cancer called a soft tissue sarcoma. This is because phyllodes tumours start from the same types of cells that are abnormal in soft tissue sarcomas rather than the types of cells found in more common types of breast cancer.

Reference

• Ellis et al. Phyllodes tumour of the breast. In Textbook of Uncommon Cancer 3rd Edition. Editors Raghavan et al 2006.