A breast cyst is a small, fluid-filled lump that can appear in the breast tissue. Best cysts are typically palpable, and are usually soft, like a grape, but can be firm in some cases.

Breast cysts are very common change, especially after the age of 40, and are normally only noted by a doctor or during a breast self-examination, as they rarely causes pain or discomfort.

Although the risk of cancer is low, whenever a possible cyst is identified, it is very important to consult a family doctor or gynecologist for testing, such as a mammogram or ultrasound, to further evaluate its characteristics and ensure that it is not another type of change that could be malignant .

Main symptoms

The main symptoms associated with a breast cyst include:

Feeling of heaviness in the breast
Diffuse pain throughout the breast
Presence of one or several lumps in the breast, which can be felt when touched
Breast swelling

Most of the time, breast cysts do not cause any symptoms, and they are usually identified when the doctor performs a breast assessment or when the woman performs a self-examination. However, when the cyst grows or if several cysts are present, women are more likely to experience other symptoms.

A breast cyst can affect one or both breasts, and it usually increases in size during a period and reduces shortly afterwards. Breast cysts that do not decrease should be further assessed by a doctor to check for signs of malignancy.

Confirming a diagnosis

The diagnosis of a breast cyst is confirmed by a family doctor, breast specialist or gynecologist through a physical examination and imaging tests. Imaging tests, like a breast ultrasound or mammogram, can help to identify the cyst size and other characteristics.

Types of breast cyst

Breast cysts can be classified into types according to the characteristics observed in the imaging exam. The main types include:

Simple cysts: these are soft, fluid-filled and have regular walls
Complex or solid cysts: these have some solid tissue inside and have thicker, more irregular edges
Complicated or thick cysts: they are formed by a thicker liquid, similar to gelatin

Based on the test results and type of cysts identified, the doctor can assess whether there is a suspicion of malignancy, and if a biopsy or surgical removal is advised. Breast cysts with benign findings do not require any type of treatment.

What causes breast cysts?

A breast cyst is a relatively common change, especially after the age of 35/40, which occurs, most of the time, due to the accumulation of fluid inside a breast gland.

Learn more about what can cause a lump in the breast and how these can be treated.

Treatment options

Breast cysts do not usually require treatment, as, in most cases, they are benign and are not harmful. However, the doctor may opt to monitor the breast cyst over several months to determine whether it increases in size or produces any type of symptom.

If the breast cyst increases in size or presents with any other changes, malignancy may be suspected and, therefore, the doctor may aspirate the fluid from the cyst to assess it for any cancer cells in the lab.

Ongoing follow-up

After identifying a breast cyst, it is common for the gynecologist to advise the woman to undergo regular follow-up, which includes a mammogram or breast ultrasound every 6 to 12 months. These tests make it possible to assess whether, over time, there are changes in the cyst's size, shape, or density, or to see whether other symptoms are noted.

In most cases, breast cysts are benign and remain stable over time. However, if there are any changes, the doctor may suspect malignancy and, may advise a needle aspiration of the fluid to assess it in the lab.

When aspiration is ordered

Aspiration is a relatively simple procedure where the doctor inserts a needle through the skin into the cyst and aspirates the fluid inside of it. Typically, this procedure is performed when malignancy is suspected or if the cyst causes symptoms or discomfort.

Depending on the characteristics of the aspirated liquid, further tests may or may not be ordered:

Fluid without blood and cyst resolves: normally no further examination or treatment is necessary;
Fluid with blood and cyst that does not resolve: malignancy may be suspected and, therefore, the doctor sends a sample of the fluid to the laboratory;
No fluid aspirated: the doctor may order other tests or a biopsy of the solid part of the cyst to assess the risk of cancer.

After aspiration, the doctor may recommend that the woman use painkillers to reduce pain, in addition to recommending rest for around 2 days.