Breast Cyst

Breast cysts are a very common diagnosis among women and one of the most common reasons for a referral to a breast clinic. They represent the most common cause of breast mass or breast symptoms in general. Breast cysts are part of a larger benign disease process known as fibrocystic disease of the breast. This disease process is a wide spectrum of both fibrous and cystic changes in the breast tissue. The simple breast cyst forms as an aberration in the natural breast development and is composed of an epithelium lined fluid-filled cavity within the surrounding breast parenchyma. They can vary from small microcysts to large macrocysts and can be single or multiple. These cysts can be entirely asymptomatic and only discovered incidentally, or can be symptomatic, presenting as lumps, pain, or associated nipple discharge. Many studies report that in women, the lifetime prevalence of fibrocystic breast disease might be between 70% and 90%. Fibrocystic changes are classified as nonproliferative, proliferative without atypia, or proliferative with atypia. While the pain and palpable mass can be worrisome to patients, pain as a symptom of breast malignancy is exceedingly rare. Furthermore, fibrocystic disease by itself is not strictly a risk factor for the development of breast malignancy. While the simple breast cyst is a nonproliferative benign disease process, atypia (or atypical ductal hyperplasia) in fibrocystic disease does have a malignant potential, and there are other malignant cystic lesions which can occur and can appear very similar in nature. The relationship between fibrocystic changes and breast cancer is complicated and controversial. Because of this, proper diagnosis, treatment, and management of breast cysts are essential.