What is fibrocystic breast disease

Fibrosis of the breast is a common breast disease. The most common patients are between the ages of 25 and 35, especially before the cessation of menstruation, when the incidence rate is highest. However, the disease will not continue to develop after complete menopause. Few people will get this disease during puberty. The cause is related to the secretion of ovarian hormones. Excessive or insufficient secretion will affect the symptoms.

1. Non-hyperplastic fibrocystic changes

(1) Macroscopically, the disease is usually bilateral, with multiple nodules and unclear boundaries. The cysts vary in size and number. The clustered small cysts and proliferating interstitial fibrous tissues are interlaced, resulting in a mottled appearance. Large cysts are called blue-domed cysts because they contain translucent turbid fluid and have a blue outer surface.

(2) Under the microscope, the epithelium covering the cyst may be columnar or cuboidal, but most are flat epithelium. The epithelium may also be completely absent, with only the fibrous cyst wall. Calcification is occasionally seen in the cavity. If the cyst ruptures, the contents overflow into the surrounding stroma, which may cause inflammatory reaction and proliferation of interstitial fibrous tissue, and the fibrotic stroma may further undergo hyaline degeneration.

Apocrine metaplasia is often seen in the cyst epithelium. The cells are larger in size, with eosinophilic cytoplasm and typical apocrine secretory protrusions on the top of the cytoplasm. The morphology is similar to that of the epithelium of apocrine glands.

2. Hyperplastic fibrocystic changes

In addition to cyst formation and stromal fibrosis, proliferative fibrocystic changes are often accompanied by proliferation of terminal duct and alveolar epithelium. Epithelial hyperplasia can increase the number of layers and form nipples that protrude into the cysts. The tops of the nipples fit together to form a sieve-like structure. When cysts are accompanied by epithelial hyperplasia, especially when there is epithelial dysplasia, they may evolve into breast cancer and should be regarded as precancerous lesions.

3. Classification: According to the severity of epithelial hyperplasia, it is divided into (1) mild hyperplasia; (2) vigorous hyperplasia; (3) atypical hyperplasia; (4) carcinoma in situ.

Non-proliferative fibrocystic changes have no risk of secondary invasive cancer, while the risk of canceration in inflammatory proliferative fibrocystic changes increases by 1.5-2 times. The chance of atypical ductal and lobular hyperplasia evolving into invasive cancer increases by 5 times, while the possibility of ductal and lobular carcinoma in situ further developing into invasive cancer increases to 10 times. This shows that fibrocystic breast disease has certain similarities with breast cancer in terms of clinical, radiographic and pathological changes, and does have a certain relationship with the occurrence of cancer. However, whether it develops into breast cancer depends mainly on the degree of ductal and alveolar epithelial hyperplasia and the presence or absence of atypical hyperplasia.