CYST VS. TUMOUR: WHAT’S THE DIFFERENCE?

If you find a lump or bump, it may be a cyst or tumour. These are two common types of lumps which look similar, but have distinct characteristics.

Cysts can appear anywhere in the body, but most frequently occur in the skin, ovaries, breasts, or kidneys. They are fluid-filled sacs that are usually benign (noncancerous). They can vary in size, from as small as a grain of rice to as large as a golf ball, and there may be more than one cyst present. They can form for no apparent reason but may be caused by blocked ducts or an injury.

Breast cysts typically occur due to hormonal fluctuations during a woman’s menstrual cycle, making them most common in women between the ages of 30 and 50. Breast cysts do not increase the risk of developing breast cancer and often do not require treatment.

Tumours form when a mass of abnormal cells accumulates in tissue. Unlike cysts, tumours are solid masses and can either be benign (noncancerous) or malignant (cancerous).

• Benign tumours: These do not spread to other parts of the body and are not usually life-threatening. Most lumps are benign but some can be premalignant (may become cancer).
• Malignant tumours: Also known as cancer, malignant tumours begin as a lump or calcium deposit resulting from abnormal cell growth. Cancer can be localized in certain tissue, like the breasts, or metastatic (spread to another part of the body).

Differences between cysts and tumours can be difficult to determine without medical attention. It’s important to consult with your doctor about any changes in your body, including new lumps and pain.

HOW ARE LUMPS DIAGNOSED?

To diagnose lumps and cysts, your doctor will likely first perform a physical exam and then order medical imaging, such as ultrasound, mammography (for lumps and cysts in breast tissue), or both together.

An ultrasound uses high-frequency sound waves to help determine the composition of a lump or area of concern, distinguishing between a cyst, fibroglandular tissue, and a solid mass. The pitch, direction, and distance sound waves travel differ depending on what they run into (e.g., tissue, fluid, bone). A computer can interpret this information as a two-dimensional image on a screen and provide information about the area of concern.

For example, an ultrasound can help determine whether the cyst is filled with fluid, solid areas, or a combination of both. By examining the features of the cyst as presented on the ultrasound image, the radiologist can assess whether the cyst has features that may be concerning and might require a biopsy.

Mammography uses X-ray technology to create a detailed picture of the internal structure of breast tissue. This exam can help spot a breast cyst, calcifications, masses, changes in the breast tissue or an area that needs further investigation. When investigating lumps or cysts, a breast ultrasound may also be ordered to complement the mammogram and allow for more comprehensive imaging of the area in question.

A biopsy is a procedure that removes small pieces of tissue from within the breast. A needle is guided into the area of concern to take a small tissue sample, which is sent to a laboratory for analysis.

WHAT HAPPENS DURING THIS IMAGING?

During mammography, the machine will gently press down on the breasts to spread the breast tissue out and capture a more complete picture of each breast. The pressure lasts for a few seconds, while the machine quickly takes a number of pictures. Then the process will be repeated for the other breast. It may be a bit uncomfortable, but it’s very quick, only 10 or 15 minutes in total.

All Mayfair Diagnostics’ mammography clinics use technology that provides 3D images (tomosynthesis) of the breast that can then be viewed in slices. This provides a greater level of detail and a clearer view of the breast tissue with a very small dose of radiation.

During an ultrasound, a warm, non-scented, hypo-allergenic ultrasound gel will be applied to the area in question. The sonographer moves the handheld probe slowly over the area. In the case of breast ultrasound, this will likely include all areas of each breast and into the armpit area to provide a complete set of images. A general ultrasound takes about 20 minutes, while breast ultrasound can take up to an hour to scan both breasts.

For both exams, you may want to let your technologist know the location of any lumps or areas of pain.

Once the mammogram and/or ultrasound images have been taken, one of our radiologists will look over them very carefully to check for possible abnormalities or changes compared to previous ultrasounds or mammograms.

HOW DO I GET MEDICAL IMAGING?

If you have pain or a concern about a lump, you will need to speak to your doctor about your family history, your medical history, and whether ultrasound, mammography, or both are needed. Your doctor will fill out a requisition for the appropriate imaging and fax it to us, or you can call to book the appointment yourself.

Breast cysts don’t increase your risk of breast cancer, but they may complicate breast screening if you have them or develop them regularly. On a mammogram, breasts cysts may make it challenging to monitor or find changes in breast tissue. For this reason, it’s recommended that you:

• Understand what’s normal for you, especially during your menstrual cycle.
• Speak to your doctor about any changes or new concerns, such as new lumps, pain, skin changes, nipple discharge, etc.

If you have breast cysts or develop them regularly, your doctor may recommend yearly breast screening that includes both mammography and breast ultrasound. Regular breast cancer screening through mammography is considered the best way to assess the health of breast tissue and catch breast cancer early in its early, most treatable stage.

Many people start having regular mammograms every year at age 40, since Alberta Health Care covers one mammogram per year starting at that age. The Canadian Association of Radiologists and Mayfair Diagnostics recommend screening mammography every year from age 40 to 49, then every two years between age 50 and 75, if there are no risks factors that would necessitate a shorter interval. After age 75, screening frequency will depend on many factors, including your medical history.

Refer to the Alberta and Saskatchewan provincial breast screening programs for their screening recommendations.

In Alberta, if your doctor hasn’t told you that you need a mammogram, you can still book your exam. You don’t always need a doctor’s requisition to book a screening mammogram. In certain instances, you are able to self-refer. See mammogram self-referral guidelines.

Mayfair Diagnostics has 13 ultrasound and mammography locations in Calgary, one in Cochrane, and one in Regina. Our Cochrane location and 12 of our Calgary locations use the Senographe Pristina mammography system – which helps provide a more comfortable mammogram. Visit our breast imaging page for more information.

REFERENCES

Canadian Cancer Society (2024) “What is breast cancer?” cancer.ca. Accessed July 11, 2024.

Canadian Cancer Society (2024) “Breast cysts.” cancer.ca. Accessed July 10, 2024

Demarco, C. (2022)  “Breast cysts and breast cancer: How can you tell the difference?” mdanderson.org. Accessed July 10, 2024.

Radiological Society of North America (2024) “Breast Cancer – Diagnosis, Evaluation and Treatment” radiologyinfo.org. Accessed July 15, 2024.

Smith, C. (2020) “Tumour vs Cyst: Differences, Diagnosis and Treatments.” treatcancer.com. Accessed July 19, 2024.

Victoria State Government, Department of Health (2014) “Cysts.” betterhealth.vic.gov.au. Accessed July 16, 2024.