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The breasts can be the cause for much concern. As they can become affected by benign and malignant tumours, they always require particular attention. Fibroadenomas count as one of the various types of tumours which can appear in breasts. Fibroadenomas of the breast are very common, benign cysts which may be observed at any age.

What Are Fibroadenomas of the Breast?

Fibroadenomas of the breast are benign breast tumour which are very common in young women (10%). They are made up of fibrous (fibro) and glandular (adeno) tissue. Fibroadenomas form a hard, mobile lump, which can be felt easily inside the breast. Sometimes, this condition is uncovered coincidentally as it appears on a mammography or on an ultrasound scan, particularly when the fibroadenoma itself is small and the breast comparatively large. Fibroadenomas of the breast may occur at any age. However, they are most frequent in women between the ages of 15 and 35.

What Are the Characteristics of Fibroadenomas?

Fibroadenomas of the breast have a number of main characteristics which help in their identification:

  • Its size: Fibroadenomas of the breast manifests themselves in the form of cysts measuring between 1 cm and 15 cm. The most common size for fibroadenomas is 2 cm to 3 cm. Fibroadenomas measuring over 5 cm are considered a “giant” mass.
  • Its location: This benign tumour can appear in any area of the breast. Fibroadenomas are likely to develop in one or in both breasts.
  • Its aspect: A breast fibroma appears smooth, firm, and well defined. It is distinguished by the fact that it does not adhere to the skin or other tissue present in the breast.
  • Fibroadenomas of the breast may form a single or multiple cysts. When a woman has more than 5 fibroadenomas, doctors refer to the condition as mammary polyadenomatosis.

The causes behind the development of fibroadenomas are still unknown. An increased sensitivity to oestrogens in certain areas of the breast might explain why these benign tumours appear. It can also be observed that females between the ages of 15 and 35 with denser breasts and a greater proportion of fibroglandular tissue to fatty tissue are more likely to develop mammary gland fibroadenomas.

What Is the Difference Between Simple Fibroadenomas and Complex Fibroadenomas?

Simple fibroadenomas are the most common. The size of this benign tumour ranges from 1 cm to 3 cm. It is firm and smooth and does not increase the risks of developing breast cancer.

In some cases, fibroadenomas are described as complex. Fibroadenomas are known as complex when the lump has cysts and calcifications. On rare occasions, this type of tumour is also linked to breast cancer. The relation between complex fibroadenomas and phyllodes tumours has yet to be established. Phyllodes tumours are mammary tumours – most often benign – which can evolve into malignant tumours.

What Is the Connection Between mammary Fibroadenomas and Pregnancy?

It has been observed that mammary fibroadenomas often appear in females of childbearing age and may develop during pregnancy. This mass may also grow during the breastfeeding period. A fibroadenoma that develops during pregnancy or breastfeeding may be explained by an increased sensitivity to the hormone oestrogen. In most cases, the evolution of the mammary fibroadenoma remains stable or recedes after menopause.

What Are the Clinical Signs of Mammary Fibroadenomas?

Mammary fibroadenomas tend to occur in young women between the ages of 20 and 30. Several clinical signs and symptoms may alert a patient as to the development of this type of tumour:

  • The mass develops slowly and is usually small and mobile when compared to the skin and to the rest of the breast.
  • The outlines of a fibroadenoma are well defined.
  • The mass is firm and rubbery. It usually forms a single lump. However, it is possible to observe several masses from the start or as the condition evolves.
  • The size of a fibroadenoma does not increase during the menstrual cycle, though it may get larger during the course of a pregnancy and while breastfeeding.
  • Mammary fibroadenomas are not associated with a swelling of the lymph nodes, particularly in the underarm area.
  • In most cases, fibroadenomas do not cause any specific pain. A painful fibroadenoma may be explained by hormonal issues, specifically during pregnancy and breastfeeding. When a fibroadenoma is painful, it may be removed through a surgical procedure.

How Is a Breast Fibroadenoma Diagnosed?

More often than not, mammary fibroadenomas go unnoticed. Screenings are performed by doctors during clinical breast exams. This benign tumour’s aspect and characteristics make it very easy to identify. Some patients who perform self-breast exams might even feel the lump themselves and schedule a meeting with their doctor.

Testing for fibroadenomas of the breast is an essential practice. Even though this condition is benign, a diagnosis is crucial if only to ascertain that the lump was not mistaken for a different type of breast tumour. It is therefore highly recommended to have regular appointments with your doctor as part of your breast cancer screening habits.

The presence of a fibroadenoma of the breast may be suspected during a routine breast exam. A mammogram, an ultrasound scan, or even, in some cases, a fine-needle aspiration biopsy (histopathological analysis) confirms the diagnosis.


The mammogram (or mammography) is a radiographic examination (X-ray) of the breast, which is used to detect any potential tissue abnormality, particularly around the mammary gland.

This exam is performed using a dedicated mammography unit. The breast is placed in a specific compartment and gradually compressed to produce an X-ray image. Fibroadenomas of the breast may be detected during a routine mammogram. The radiologist who carries out the exam can identify a nodule in the form of a well-defined opaque area. The presence of small calcifications may confirm that the fibroid has been there for a while.

Breast Ultrasound

A breast ultrasound may complete the mammogram in order to provide a more in-depth analysis of the anomaly previously detected. It is also suitable when the density of the breasts is not sufficient to get a good-quality mammography. This is specifically the case in younger patients. In pregnant women, the ultrasound is also favoured over mammograms because it does not rely on X-rays, which are contraindicated during pregnancy.

Once the radiologist has interviewed the patient to establish her history of illness and any conditions that run in her family, a clinical breast exam is performed. Then, the radiologist applies a gel designed to ensure contact between the skin and the ultrasound probe. This exam makes it possible to measure the exact size of the nodule and to confirm that the fibroadenoma does indeed have a homogenous aspect, with clear, well-defined outlines. The ACR (American College of Radiology) classification ranks the images obtained from the mammography. For instance, a mammography image showing an acr2 fibroadenoma of the breast assesses that the anomalies are benign and require no monitoring or follow-up exams.

Histological Analysis

A histological analysis consists in performing an exam under a microscope in order to establish the nature of the tumour’s cells. In most cases, the physician will extract cells using a fine needle or perform a biopsy. This exam is necessary in cases where previous results were not sufficient to establish the benign nature of the mass, or where the mass shows specific characteristics.

How to Treat Mammary Fibroadenomas?

Fibroadenoma treatment in Paris varies from one patient to another. In most cases, the doctor will opt for therapeutic abstention. Fibroadenomas of the breast do not require any operation if the nodule is smaller than 2 cm in size and if it is identified in patients under 35.

  • Simple monitoring: when a fibroadenoma is small, painless, and shows no risk factor regarding breast cancer. However, regular check-ups remain necessary.
  • Echo therapy: this technique consists in focusing high-density ultrasounds onto the lesion. The rays induce an increase in temperature up to 85°C, which melts the targeted tissue.
  • Surgical treatment: in cases where the lesion is larger than 2 cm, when the fibroadenoma is painful, and when the patient is psychologically affected by the lump. Anxiety, stress, and fear of breast cancer justify wanting to schedule an operation to remove the fibroadenoma from the breast. If monitoring proves challenging and the patient is under a higher risk of breast cancer, the doctor will also usually advise for the surgical removal of the mass.

What to Expect During a Fibroadenoma Operation?

The procedure is performed by a plastic surgeon and covered, at least partly, by your national health service. The intervention may be done under local anaesthesia when the lesion is small and superficial. It is usually done under general anaesthesia and requires about 30 minutes, in outpatient surgery. The patient will be admitted to the hospital in the morning and will be able to go home that same evening.

After just a few months, the scar will be practically invisible. If the procedure is carried out by a plastic surgeon, the scar itself will be placed somewhere discrete, such as the areola or the inframammary fold rather than right in the middle of the breast. The sutures are absorbable. In most cases, no drainage is required, and breast reconstruction is not necessary.

Doctor Vincent Masson specialises in plastic, reconstructive and cosmetic surgery. He routinely performs several types of procedures ranging from basal cell carcinoma and squamous cell carcinoma removal, to the excision of malignant melanoma, all the way to calf prostheses and reconstructive surgery following an accident.

The breast may feel harder for the first few weeks. Sport is contraindicated for 1 month and a 2 to 3-day work interruption is recommended depending on your profession. The procedure is not very painful.

As a precaution, once extracted, the fibroadenoma is sent out to be tested in any case. Local recurrence is rare, although some cases have been reported.

Can fibroadenoma Turn into Cancer?

It is possible, albeit very rare, for fibroadenomas to develop into cancer. Fibroadenomas are not unlike phyllodes tumours, where the risk of metastases is considered high. However, fibroadenomas of the breast are not malignant. As for phyllodes tumours, they account for less than 1% of all breast cancers.


Dr Vincent Masson is a plastic surgeon with a post-graduate diploma in plastic, reconstructive and aesthetic surgery and a gold medal in surgery from the Paris Hospitals. He is a former senior registrar and attaché at the Hôpital Saint Louis.

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