Porth's Essentials of Pathophysiology, 4e

1038

Genitourinary and Reproductive Function

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SUMMARY CONCEPTS

and often is associated with hyperinsulinemia and insulin resistance. Cancer of the ovary is the second most common female genitourinary cancer and the most deadly. A family history of cancer, particularly breast and ovarian cancer, and nulliparity increase the risk of developing ovarian cancer, whereas oral contraceptive use, pregnancy, and lactation decrease the risk.

■■ The female external genitalia are affected by disorders that affect skin on other parts of the body. Bartholin cysts, which are the result of occluded ducts in Bartholin glands, are often painful and can become infected. Vulvodynia is a chronic vulvar pain syndrome with several classifications and variable treatment results. Cancer of the vulva, is an uncommon malignant neoplasm, which accounts for 3% to 5% of all genital cancers in women. ■■ The normal vaginal ecology depends on a delicate balance of hormones and bacterial flora. Vaginitis or inflammation of the vagina is characterized by vaginal discharge and burning, itching, redness, and swelling of vaginal tissues. It may be caused by chemical irritants, foreign bodies, and infectious agents. Primary cancers of the vagina are uncommon, accounting for 1% of all cancers of the female reproductive system. ■■ Disorders of the cervix and uterus include inflammatory conditions such as cervicitis and endometritis. Endometriosis is a condition in which functional endometrial tissue is found in ectopic sites outside the uterus. Cervical cancer is caused by HPV and arises from precursor lesions that can be detected on Pap smear cytology, and if detected early, is the most easily cured of all the cancers of the female reproductive system. Endometrial cancer is the most common cancer of the female pelvis. Leiomyomas are benign neoplasms of the uterine wall. ■■ Pelvic inflammatory disease (PID) is an inflammation of the upper reproductive tract that involves the uterus (endometritis), fallopian tubes (salpingitis), or ovaries (oophoritis). ■■ Disorders of uterine support result from weakness and relaxation of the pelvic floor muscles. Cystocele and rectocele involve herniation of the bladder or rectum into the vagina. Uterine prolapse occurs when the uterus bulges into the vagina. ■■ Disorders of the ovaries include cystic disorders, polycystic ovary syndrome (PCOS), and cancer of the ovary. Functional cysts usually are asymptomatic unless there is substantial enlargement or bleeding into the cyst or the cyst becomes twisted or ruptures. Polycystic ovary syndrome is a disorder characterized by various degrees of hirsutism, obesity, and infertility,

Menstrual Disorders Between menarche (i.e., first menstrual bleeding) and menopause (i.e., cessation of menstruation), the female reproductive system undergoes cyclic changes called the menstrual cycle . This includes the maturation and release of oocytes from the ovary during ovulation and periodic vaginal bleeding resulting from the shedding of the endometrial lining. The menstrual cycle produces changes in the breasts, uterus, skin, ovaries, and perhaps other unidentified tissues. Dysfunctional Menstrual Cycles Dysfunctional menstrual cycles may take many forms, including dysfunctional bleeding, and amenorrhea (absence of menstruation) is failure to menstruate, hypomenorrhea (scanty menstruation), oligomenor- rhea (infrequent menstruation, periods more than 35 days apart), polymenorrhea (frequent menstruation, periods <21 days apart), menorrhagia (excessive men- struation), or metrorrhagia (bleeding between peri- ods). 45 Menometrorrhagia is heavy bleeding during and between menstrual periods. Although unexplained bleeding can occur because of pregnancy, spontaneous abortion, neoplasms, or other reasons, the frequent cause in the nonpregnant woman is a condition commonly called dysfunctional bleed- ing . Dysfunctional bleeding is related to alterations in the hormones that support normal cyclic endometrial changes. Estrogen deprivation causes retrogression of a previously built-up endometrium and bleeding. Such bleeding often is irregular in amount and duration, with the flow varying with the time and degree of estro- gen stimulation and with the degree of estrogen with- drawal. 45 A lack of progesterone can cause abnormal menstrual bleeding. In its absence, estrogen induces development of a much thicker endometrial layer with a richer blood supply. Periodic bleeding episodes alternating with amenor- rhea are caused by variations in the number of function- ing ovarian follicles present. When too many follicles are present and active, high levels of estrogen develop, causing the endometrium to proliferate for weeks or even months. In time, either of two events occurs that lead to an estrogen deficiency and bleeding: several follicles may