April 20, 2020

Breast Cysts

What is a Breast Cyst? The breast is a complex gland consisting of ducts, lobules, connective tissue, and fat. On average, a typical breast contains 12-15 major lobules and the same number of major ducts, the function of which is to carry milk out through the nipple during lactation. These ducts and lobules are, in turn, made of hundreds of microscopic ductal cells and lobular cells.


Generally, when there is an outpouching of the duct, a cyst forms. The cyst can remain in continuity with the duct or can “pinch off” and form a separate entity. A breast cyst is a fluid filled sac located in the breast usually containing greenish, straw colored, or brownish fluid.  They are generally round with smooth edges containing fluid. 


What is the cause of breast cysts? The cause of breast cysts is unclear but their formation is likely related to hormonal changes in the body. They are more common in premenopausal women (women of reproductive age) than women of other age groups and tend to become tender and/or larger around menses and pregnancy. 


What are the symptoms of breast cysts? Breast cysts are smooth, palpable lumps with distinct borders. Sometimes they are completely asymptomatic and only discovered when a woman goes for her routine imaging (mammography, sonography). Other cysts present as an asymptomatic mass fitting the description above. Still others can be larger and painful, especially around menses or pregnancy. When they become large and/or painful, aspirating them or removing them may be considered.  


Do breast cysts go away on their own? Breast cysts can go away on their own, although if the cyst is large (>2cm), it is unlikely that the cyst will regress spontaneously. If a patient is experiencing discomfort and the cyst is readily palpable, it can be drained using a typical syringe and medium to large bore needle. If the cyst is deeper, nonpalpable or painful, aspiration can be performed by the breast imager using the same technique, but relying upon the ultrasound as a guide to find the cyst requiring aspiration.


Can a cyst in the breast turn into cancer? A breast cyst technically can turn into a cancer or represent a cancer at presentation, but this occurs very rarely. The bigger problem occurs when the patient has a cyst that presents as a mass on the exam and can make it more difficult to recognize a concomitant malignancy (malignancy occurring at the same time as a cyst). Both on physical exam and even on imaging, a breast cyst can obscure an underlying cancerous mass. As you will read below, if cysts are aspirated and found to contain bloody fluid and/or the cyst reaccumulates after 2 aspirations, the fluid should be sent for cytologic analysis to rule out carcinoma.


How long will a breast cyst last? A breast cyst can last from time of presentation through the reproductive years or even remain throughout the lifetime of a patient, but they’re generally not dangerous. 


How to prevent breast cysts? It is unclear how to prevent breast cysts. They are not, in and of themselves, dangerous, so prevention is not the key issue here. The key issue is whether or not to aspirate them, resect them, or just observe them ensuring they don’t change significantly over time or obscure an adjacent tumor.  


How to tell the difference between a cyst and a tumor? A cyst on a physical exam presents as a smooth mass with distinct borders, whereas a malignancy generally feels like a firm, non-movable mass with indistinct or “rough” borders. In contrast to a benign breast cyst, a cancerous mass may also present with puckering of the skin, nipple inversion, tumescent skin (‘piel d’orange skin), skin dimpling, asymmetries, redness or inflammatory changes, and/or enlarged axillary lymph nodes (the lymph glands under the armpits). On a mammogram, the cyst will look like a perfectly smooth, balloon-like mass, whereas malignancies can present as calcifications or what’s called a ‘spiculated mass,’ where it appears to almost be “sucking” the tissue around it.  On ultrasound, a cyst is a fluid filled sac, whereas malignancies have their own typical appearance: taller rather than wide, ill-defined borders, the shadowing pattern on ultrasound also characteristic of malignancy.  


What is the treatment for breast cysts? Most can just be left alone and safely watched over time. However, they can grow large (>2cm or so), at which point they may be painful, warranting drainage. Note: if the cyst fluid re-accumulates more than twice or is bloody, the fluid should undergo cytologic testing to ensure it’s not a rare presentation of cancer. Clearly, if the aspirate is concerning for malignancy or pre-malignancy, the mass should be excised with appropriate margins. 


Can diet affect the breast cysts? This is controversial, but perhaps food high in estrogen content, such as all soy products (phytoestrogens), should be minimized or avoided in the adult patient. 


Can you suggest some home remedies and self-care tips for women having a breast cyst? There is no evidence showing the efficacy of a home remedy, although Evening Primrose Oil is a supplement derived from a yellow flower. The therapeutic activity of evening primrose oil is attributed to the direct action of its essential fatty acids on immune cells as well as to an indirect effect on the synthesis of eicosanoids. Evening Primrose Oil contains linoleic acid and gamma linoleic acid (thought to have mild anti-inflammatory properties) may be effective at reducing pain women might feel due to a breast cyst and/or cystic breasts.


Can breast cysts repeat even after treatment? The cysts can reaccumulate if drained (see above). If the cysts are removed surgically, they generally don’t recur, but people prone to breast cysts can experience new ones. While they may be inconvenient and uncomfortable, they are rarely if ever dangerous and do not represent a risk factor for breast cancer.