Porth's Essentials of Pathophysiology, 4e

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Disorders of the Female Genitourinary System

C h a p t e r 4 0

hygiene, intestinal parasites, or the presence of foreign bodies. Candida albicans, Trichomonas vaginalis , and bacterial vaginosis are the most common causes of vagi- nitis in the childbearing years, and some organisms can be transmitted sexually 15,16 (see Chapter 41). The decrease in estrogen levels that occurs during peri- menopause and post menopause can lead to an atrophic form of vaginitis. Estrogen deficiency results in a lack of regenerative growth of the vaginal epitheliumand changes in the vaginal pH and flora, rendering these tissues more susceptible to infection and irritation. Döderlein bacilli disappear, and the vaginal secretions become less acidic. The symptoms of atrophic vaginitis include itching, burning, and dyspareunia. These symptoms usually can be reversed by local application of estrogen. Every woman normally experiences vaginal discharge during the menstrual cycle, but it should not cause burn- ing or itching or have an unpleasant odor. These symp- toms suggest inflammation or infection. Because these symptoms are common to the different types of vagi- nitis, precise identification of the organism is essential for proper treatment. A careful history should include information about systemic disease conditions, the use of drugs such as antibiotics that foster the growth of yeast, dietary habits, stress, and other factors that alter the resistance of vaginal tissue to infections. A physical examination usually is done to evaluate the nature of the discharge and its effects on the genital structures. Microscopic examination of a saline wet-mount smear is the primary means of identifying the organism responsi- ble for the infection. 15 Culture methods and deoxyribo- nucleic acid (DNA) probe tests may be needed when the organism is not apparent on a wet-mount preparation. Cancer of theVagina Primary cancers of the vagina are extremely rare, accounting for approximately 1% to 2% of all can- cers of the female reproductive system. 6,7,11 Like vulvar carcinoma, cancer of the vagina is largely a disease of older women, with a peak incidence between 60 and 70 years of age. 7 Vaginal cancers may also result from local extension of cervical cancer, from exposure to sexually transmitted HPV, or rarely from local irritation such as occurs with prolonged use of a pessary. Smoking and human immunodeficiency virus (HIV) infection also increase the risk of vaginal cancer. Approximately 70% of vaginal cancers are squamous cell carcinomas, with other less common types being adenocarcinomas (15%), malignant melanomas (9%), and sarcomas (up to 4%). 17 Squamous cell carcinomas begin in the epithelium and progress over many years from precancerous lesions called vaginal intraepithelial neoplasia (VAIN). Not infrequently, squamous cell car- cinoma develops some years after cervical or vulvar car- cinoma, a sequence that supports the carcinogenic effect in the lower genital tract related to HPV infection. The most common symptom of vaginal carcinoma is abnormal bleeding. Other signs or symptoms include an abnormal vaginal discharge, a palpable mass, or dyspareunia. Most women with preinvasive vaginal carcinoma are asymptomatic, with the cancer being

discovered during a routine pelvic examination. The anatomic proximity of the vagina to other pelvic struc- tures (urethra, bladder, and rectum) permits early spread to these areas. Pelvic pain, dysuria, and constipation are associated symptoms. Since most preinvasive and early invasive cancers are silent, the routine use of vaginal cytology (Papanicolaou [Pap] smear) is the most effective method of detection. Diagnosis requires biopsy of suspect lesions or areas. Because vaginal cancer is rare, there is not standard treatment. 11 Both radiation and surgical methods are used, with the treatment plan being determined by the cancer type, stage of the disease (i.e., size, location, and spread), and the woman’s age. 11 Disorders of the Uterine Cervix The cervix is composed of two types of epithelial tis- sue: stratified squamous and columnar epithelium. The exocervix, or visible portion, is covered with stratified squamous epithelium, which also lines the vagina. The endocervix, which is the canal that leads to the endo- metrial cavity, is lined with columnar epithelium that contains large, branched mucus-secreting glands. The amount and properties of the mucus secreted by the gland cells vary during the menstrual cycle. Blockage of the mucosal glands results in trapping of mucus in the deeper glands, leading to the formation of dilated cysts in the cervix called nabothian cysts . These are benign cysts that require no treatment unless they become so numerous that they cause cervical enlargement. The junction of the squamous epithelium of the exo- cervix and mucus-secreting columnar epithelium of the endocervix (i.e., squamocolumnar junction) appears at various locations on the cervix at different points in a woman’s life (Fig. 40-8). During childhood, the squamo- columnar junction is located just inside the external os. High levels of hormones which occur during puberty, first

Columnar epithelium

D

A

C

Squamous epithelium

B

A. Menarchial B. Menstruating C. Menopausal D. Postmenopausal FIGURE 40-8. Location of the squamocolumnar junction (transformation zone) in menarchial, menstruating, menopausal, and postmenopausal women.