Fibroadenomas are benign (non-cancerous) tumours of the breasts. They are solid tumours formed by growth of both glandular tissues and stromal (connective) tissues. Fibroadenomas can appear as single or multiples. They can occur in one side or both sides of the breasts at the same time. Fibroadenomas come in various sizes and larger ones can even grow up to > 5cm.
What causes fibroadenomas?
It is not known what actually causes fibroadenomas, but it is generally believed that the growth of fibroadenomas is related to the hormone oestrogen. Fibroadenomas are commonest in women in their 20s and 30s, but they can be found in women of any age. They tend to grow larger and become more obvious before menstruation, during pregnancy and breastfeeding. Nevertheless, they generally do not affect breastfeeding. The growth patterns of fibroadenomas vary: some can regress without any treatment, especially after menopause due to lower level of oetrogen; but some just continue to grow and progress over time.
What are the symptoms of fibroadenomas?
Fibroadenomas usually do not cause any symptoms. Many a times, they are felt as lumps in the breasts by women themselves. They are roundish with distinct borders, firm or rubbery to the touch and move easily under the skin. They are usually painless, but may sometimes be painful or feel swollen, particularly just before period.
How to make a diagnosis of fibroadenomas?
Some fibroadenomas are felt by women themselves as lumps in the breasts. Women with this symptom have to be thoroughly evaluated by a doctor with the Triple Assessment. The doctor starts with checking the medical history, family history and a clinical examination. If the doctor finds any lumps in the breasts, radiological examinations such as a mammogram and / or a formal ultrasound scan of the breasts will be necessary. A pathological examination by means of fine needle aspiration (FNA) or core needle biopsy is performed if there are concerns about the nature of the lumps.
Some fibroadenomas are too small to be felt but are only detected by radiological examinations such as a mammogram or a breast ultrasound scan during breast cancer screening. In such case, the women will still need to be evaluated by a doctor with the Triple Assessment.
Different types of fibroadenomas
Simple fibroadenoma: Most fibroadenomas are about 1–3cm in size. When looked at under a microscope, simple fibroadenomas will appear the same all over. Simple fibroadenomas have no significant increase in the risk of the woman developing breast cancer in the future.
Complex fibroadenoma: When looked at under a microscope, complex fibroadenomas contain changes such as an overgrowth of cells (hyperplasia) and thus they can grow in size rapidly. Having a complex fibroadenoma means the woman can have a very slightly increased risk of developing breast cancer in the future.
Giant fibroadenoma: Occasionally, a fibroadenoma can grow to more than 5cm in size and this is called a giant fibroadenoma. They need to be removed because they can press on or replace other breast tissues and can deform the breasts.
Giant juvenile fibroadenoma: This is not a common type of fibroadenoma. It is usually found in girls and adolescents between the ages of 10 and 18. These fibroadenomas can grow very large within a short period of time, and thus they are usually managed by surgical excision.
What are the treatments for fibroadenomas?
Most fibroadenomas remain the same size. Some get smaller and eventually disappear over time even without any treatment. Therefore, some small breast lumps that appear not suspicious on Triple Assessment can be left in place and monitored regularly to make sure they do not grow. This approach is useful for women with multiple fibroadenomas. In such cases, removing too many fibroadenomas might cause scarring that would change the shape and texture of the breasts. Hence, if the fibroadenomas are not causing any symptoms and the sizes are small, breast examinations with imaging tests at regular intervals may be recommended to monitor any changes.
The doctor will recommend surgical excision of a fibroadenoma in the following situations:
the fibroadenoma causes pain;
the fibroadenoma grows rapidly and potentially distorts the breast;
the size is significant, > 2cm;
the results of the Triple Assessment do not concur, and there is on-going suspicion about the nature of the fibroadenoma.
Is regular follow-up necessary for fibroadenomas?
It is important for women with fibroadenomas to have regular breast examinations which may include some or all of the components of the Triple Assessment as advised by the doctor. These assessments serve to make sure the fibroadenomas are not growing.
For women who have had excision of a fibroadenoma, it is also necessary for them to undergo regular breast examinations because sometimes one or more new fibroadenomas can appear again. This does not mean that the old one has come back. Rather, it means that another fibroadenoma has formed. Women with a history of complex fibroadenoma must be followed up regularly because they have a slightly increased risk of developing breast cancer in the future.
