General information Phyllodes

What is a Phyllodes tumor?

A phyllodes tumor is a lump or swelling that develops in the connective tissue of the breast. These tumors can occur as early as the age of 12 years, but the majority develop in women between the ages of 40 and 60. A few cases of a phyllodes tumor of the prostate have been reported in men.   

Phyllodes is relatively unfamiliar because it is fairly rare: fewer than 1% of breast tumors are phyllodes tumors. An important feature that differentiates a phyllodes tumor from a fibroadenoma is the often-rapid growth. These tumors have also shown a tendency to return.   

The name ‘phyllodes’ comes from the Greek and means ‘leaf-like’, referring to the structure of the tumor cells when seen under the microscope.  

Cause and heritability  

We do not know why phyllodes tumors develop or what factors are involved. There are no indications that phyllodes tumors are hereditary.  

Three gradations  

There are three gradations of phyllodes tumors: benign, borderline and malignant. The characteristics of each type are set out below.  

Benigne

• Benign tumors are the most common type, accounting for over 50% of all phyllodes tumors.  
• Non-metastatic.  
• Any recurrence will be after four years on average, but the period can be shorter or longer.  
• Appearance under the microscope: the tumor margins are well-defined, the connective tissue cells look normal, and there is little overgrowth of connective tissue cells.  

Borderline 

These tumors have a combination of benign and malignant characteristics.  

• Borderline tumors account for approximately 25% of all phyllodes tumors.  
• Non-metastatic.   
• Any recurrence will be after three years on average, but the period can be shorter or longer.  
• Appearance under the microscope: the tumor margins are fairly well-defined, the connective tissue cells look somewhat abnormal, and there is some overgrowth of connective tissue cells.  

Malignant

• Malignant tumors account for approximately 20% of all phyllodes tumors.  
• There is a slight risk of metastasis. Any metastases usually begin in the lungs, but the cancer can also spread to other parts of the body.  
• Any recurrence will be after 20 months on average, but the period can be shorter or longer.  
• Appearance under the microscope: the tumor margins are not well-defined, the connective tissue cells look abnormal, and there is substantial overgrowth of connective tissue cells.

Centers of expertise  

Local where possible, specialist if necessary  

Multidisciplinary teams at specialist hospitals (‘knowledge centers’) have most knowledge and expertise on the diagnosis and treatment of phyllodes tumors, but many treatments can be carried out at local hospitals.   

Patients can ask their doctor to contact a phyllodes tumor specialist at a knowledge center in order to decide upon the best treatment in consultation. The Dutch knowledge center for phyllodes tumors is the Antoni van Leeuwenhoek Hospital in Amsterdam.  

Fellow sufferers

Contact with fellow sufferers helps many patients to cope with a diagnosis of phyllodes tumors. Recognizing and acknowledging each other’s problems and sharing feelings can provide some peace of mind in an often-stressful situation. You can find more information about contact with fellow sufferers here.