carcinoma should be reserved for lesions resembling oat cell carcinoma of the lung. Small cell anaplastic carcinoma infiltrates diffusely and consists of tumor cells that have scanty cytoplasm, round to oval small nuclei, coarsely granular chromatin, and high mitotic activity. The nucleoli are absent or small. Immunohistochemistry or electron microscopy can differentiate the small cell neuroendocrine tumors. Patients with the large cell type of carcinoma, with or without keratinization, have a better prognosis than those with the small cell variant. Small cell anaplastic carcinomas behave more aggressively than poorly differentiated squamous carcinomas that contain small cells. Infiltration of parametrial tissue and pelvic lymph node metastasis affect the prognosis.
Other less common variants of squamous carcinoma include verrucous carcinoma and papillary (transitional) carcinoma. Verrucous carcinomas may resemble giant condyloma acuminatum, are locally invasive, and rarely metastasize. Papillary carcinomas histologically resemble transitional cells of the bladder and may have more typical squamous cell invasion at the base of the lesion. Papillary carcinomas behave and are treated in a manner similar to traditional squamous cell cancers, except that late recurrences were noted.
Adenocarcinoma There is an increasing number of cervical adenocarcinomas reported in women in their 20s and 30s. Although the total number of cases of adenocarcinoma is relatively stable, this disease is appearing more frequently in young women, especially as the number of cases of invasive squamous cell carcinoma decreases. Older reports indicated that 5% of all cervical cancers were adenocarcinomas, whereas newer reports show a proportion as high as 18.5% to 27% (29–31). Much of this proportional increase is related to a decreasing incidence
Figure 36.4 Invasive squamous cell carcinoma, large cell nonkeratinizing type. Tumor cells tive of squamous differentiation.
of squamous carcinoma secondary to screening programs (which are less accurate at identifying preinvasion adenocarcinoma), greater exposure to oral contraceptives, and a greater exposure to HPV (4,5).
Adenocarcinoma in situ (AIS) is believed to be the precursor of invasive adenocarcinoma, and it is not surprising that the two often coexist (32). In addition to AIS, intraepithelial or invasive squamous neoplasia occurs in 30% to 50% of cervical adenocarcinomas (33). A squamous intraepithelial lesion may be observed colposcopically on the ectocervix, and the coexistent adenocarcinoma often is higher in the cervical canal.
Patients with AIS who are treated with conization should undergo close clinical follow-up.
Endocervical curettage, often used in surveillance, may miss residual or invasive disease, and false-negative rates as high as 50% were reported (34). In addition, skip lesions not resected at the time of conization may be present. For these reasons, hysterectomy should be considered the standard therapy for patients who have completed their childbearing. In two reports, patients with negative cone biopsy margins were followed conservatively, with few requiring repeat surgical procedures (35,36). Because cervical AIS tends to affect women during their reproductive years, a thorough discussion of risks and benefits should take place, and treatment should be individualized.