In 1970, clear cell adenocarcinoma, a very rare tumor, was identified in a cluster of young women whose mothers took diethylstilbestrol during pregnancy to prevent threatened abortion. Follow-up studies determined that the incidence of this tumor in persons exposed to diethylstilbestrol in utero is low (<1 per 1000, albeit about 40 times greater than in the unexposed population). In about one-third of exposed women, small glandular or microcystic inclusions develop in the vaginal mucosa. These lesions appear as red, granular foci lined by mucus-secreting or ciliated columnar cells. This condition is called vaginal adenosis and is benign but is important to recognize because it is from such precursor lesions that clear cell adenocarcinoma arises.
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SarcomaBotryoidesand children younger than 5 years of age, but may occur uncommonly in young women. It also may be found in Sarcoma botryoides (embryonal rhabdomyosarcoma) is other sites, such as the urinary bladder and bile ducts. a rare form of primary vaginal cancer that manifests as It is discussed further with other soft tissue tumors in soft polypoid masses. It usually is encountered in infants Chapter 21.
Most cervical lesions are relatively banal inflammations (cervicitis), but the cervix also is the site of one of the most common cancers in women worldwide.
Inflammatory conditions of the cervix are extremely common and may be associated with a purulent vaginal discharge. Cervicitis can be subclassified as infectious or noninfectious, although differentiation is difficult owing to the presence of normal vaginal flora including incidental vaginal aerobes and anaerobes, streptococci, staphylococci, enterococci, and Escherichia coli and Candida spp.
Much more important are Chlamydia trachomatis, Urea-plasma urealyticum, T. vaginalis, Neisseria gonorrhoeae, HSV-2 (the agent of herpes genitalis), and certain types of HPV, all of which are often sexually transmitted. C. trachomatis is by far the most common of these pathogens, accounting for as many as 40% of cases of cervicitis encountered in sexually transmitted infection clinics. Although less common, herpetic infections are noteworthy because maternal–infant transmission during childbirth may result in serious, sometimes fatal systemic herpetic infection in the newborn.
Cervicitis commonly comes to attention on routine examination or because of leukorrhea. It often is treated empirically with antibiotics that are active against chlamydia and gonococcus. In some instances, nucleic acid amplification tests are used on vaginal fluid to identify the presence of these organisms as well as Trichomonas vaginalis.
Most tumors of the cervix are of epithelial origin and are caused by oncogenic strains of HPV. During development, the columnar mucus-secreting epithelium of the endocervix is joined to the squamous epithelial covering of the exocervix at the cervical os. With the onset of puberty, the squamocolumnar junction undergoes eversion, causing the columnar epithelium to become visible on the exocervix. The exposed columnar cells, however, eventually undergo squamous metaplasia, forming a region called the transformation zone, where tumors most commonly arise (
Fig. 19.4
HPV, the causative agent of cervical neoplasia, has a tropism for the immature squamous cells of the transformation zone. Most HPV infections are transient and are eliminated within months by the host immune response. A subset of infections persists, however, and some cause squamous intraepithelial lesions (SILs), which are precursors from which most invasive cervical carcinomas develop.