Uterine fibroids are muscular tumors that grow in the wall of the uterus and are usually benign. They can be classified into three different categories depending on where in the uterus they grow. Submucosal fibroids grow inside the uterine cavity, intramural fibroids grow within the wall of the uterus, and subserosal fibroids grow on the outside of the uterus. In some cases, fibroids, called pedunculated fibroids, can grow on stalks that grow out from the surface of the uterus or into the cavity of the uterus. Fibroids can grow singularly or some cases multiple can occupy the uterus. The size of the fibroid varies from about the size of an apple seed to as large as a grapefruit. In rare cases, the fibroid can become very large.
Uterine fibroids are the most common benign tumor in females with an estimated incidence of 20%–40% in women during their reproductive year. Most American women will develop fibroids at some point in their lives. By age 50, 70% of women have had fibroids. In most cases, there are no symptoms associated with fibroids but some patients (~30%) can experience heavy bleeding, feeling of nausea and fullness in the lower abdomen, enlargement of the lower abdomen, frequent urination, pain during intercourse, complications during pregnancy, headaches, back pain, or pelvic cramping.
Ovarian cysts are fluid-filled sacs that form in or on the surface of the ovaries. The most common type of ovarian cyst, called a functional cyst, form during the menstrual cycle. The most common types of functional cysts are either follicular cysts or corpus luteum cysts. Follicular cysts form when the follicle that usually releases an egg doesn’t break open causing the follicle to continue growing into a cyst. Corpus luteum cysts form when the follicle sac that usually shrinks into a mass of cells called the corpus luteum doesn’t shrink. Instead, the sac releases itself after the egg is released, and then fluid builds up inside. Other types of ovarian cysts which are less common are endometriomas, dermoids, and cystadenomas.
Most ovarian cysts do not cause symptoms. In some cases, a cyst can cause symptoms of pressure, bloating, swelling, and pain in the lower abdomen. If a cyst ruptures, very severe symptoms occur such as sudden and sharp pain.
The cause of the uterine fibroids and ovarian cysts have been suggested to be an increased level of estrogen. However, non-surgical treatment that uses estrogen agonists to reduce the circulating estrogen levels has shown only to produce temporary inhibition of the tumor or cyst growth. After the cessation of therapy, rapid regrowth of tumors or cyst usually occurs when normal hormonal fluctuations involved in the menstrual cycle are reestablished. Since the use of estrogen agonists to decrease levels of circulating estrogen has serious side-effects including bone loss and increase in blood lipid levels which increases the risk for early-onset osteoporosis and cardiovascular disease, the long-term use of estrogen agonists is precluded. Further research has pointed out that reduction of estrogen does not result in programmed cell death, apoptosis of the tumor and cyst, which explain the limited success of the estrogen agonists therapy.
The cause of the tumor and cyst development and growth is the reduction or loss of the ability to initiate the activity associated with apoptosis in the female reproductive system. In fertile women, transient inflammation and uterine lining tissue injury is a physiological and essential process during menstruation, ovulation, and parturition. However, if the damaged cells during the menstruation are not removed completely through apoptosis, the damaged cells can cause the tissue regeneration mechanism to continuously operate, leading to the development and growth of a fibroid. In addition, harmful stimuli, such as irritants or pathogens can trigger dysregulated tissue repair leading to the development and growth of a fibroid.
Mycobacterium infections to the female reproductive tract can cause tissue damage and inflammation. They can also trigger macrophages to engulf the mycobacteria. The immune system reacts to the infected macrophages to form granulomas in which the immune cells and fibroblasts aggregate to form layers surrounding the infected macrophage to seal it inside a barrier from which it cannot escape. The granulomas can lead to the formation of uterine fibroids and ovarian cysts.