Читать книгу The SAGE Encyclopedia of Stem Cell Research - Группа авторов - Страница 217

One common abnormality of the breast found in both men and women is polythelia, also known as supernumerary nipple. Polythelia is characterized by the presence of more than the normal number of two nipples. Although supernumerary nipples can be found anywhere on the body, they are most often found on the milk line, which extends from the armpit to the groin. Although not harmful, supernumerary nipples are often removed by excision because they can develop the same diseases as normal nipples.

Another common pathology of the breast is sclerosing adenosis. Sclerosis refers to a condition where the tissues in the breast harden, leading to sclerosing adenosis as well as complex sclerosing lesions or radial scars. This disease is characterized by the presence of additional tissue in the breast lobules, which can cause lumps and discomfort. Although these lumps are noncancerous, the pain associated with it sometimes gives reason for the lumps to be removed. Sclerosing adenosis is more commonly seen in women in their thirties and forties, and occur naturally as a woman ages. Although some women do experience pain that may lead to the excision of the lump, many others experience no symptoms and their condition can go unnoticed. Due to how the disease manifests itself, however, once a lump is found, most times physicians opt to obtain a biopsy of the lump to check for cancerous tumors, which are similar to the lumps of sclerosing adenosis. Complex sclerosing adenosis and radial scars are both similar to sclerosing adenosis in that they are characterized by hardening of breast tissue, and are found primarily in older women. They differ from one another only on the account of size: any lump smaller than 1 centimeter is classified as a radial scar and lumps bigger than 1 centimeter are classified as complex sclerosing lesions.

A third relatively common pathology of the breast is fibrocystic disease. Fibrocystic breasts are characterized as breasts that contain tissue that is said to be lumpy, causing unevenness of the breast and discomfort or pain. The lumpiness in the breasts is caused by noncancerous masses within the breasts, which may be cysts or masses of hardened tissue. Classically, fibrocystic disease presents with premenstrual breast pain involving multiple lesions in both breasts. These lesions also fluctuate in size. Fibrocystic breasts are common in women, especially before menstruation or during later years in a woman’s life, however it generally declines after a woman experiences menopause. Today, physicians are leaning away from considering fibrocystic breasts as a disease due to the fact that over half of women in the United States are affected by it. In addition, the masses do not indicate an increased risk of carcinoma. Histologic types include fibrosis (hyperplasia of the breast stroma), cystic (fluid filled with ductal dilation), sclerosing adenosis (increased acini with intralobular fibrosis), and epithelial hyperplasia (increased number of epithelial cell layers in the terminal duct lobule; this type, which presents in women over 30 years of age, presents with increased risk of carcinoma if atypical cells are present).

Some benign breast tumors include fibroadenoma, intraductal papilloma, and phyllodes tumor. Fibroadenoma is a small, mobile, firm mass that occurs in patients less than 25 years of age. Fibroadenomas increase in size and tenderness with increased estrogen (such as during menstruation or pregnancy). This type of mass is not a precursor to cancer. Intraductal papillomas are small tumors that grow in the lactiferous ducts, often beneath the areola. These present with serous or bloody discharge and are associated with a slightly increased risk of carcinoma. Phyllodes tumor, which may become malignant, is a large tumor of connective tissue and cysts that presents in postmenopausal women.