This is the more conventional or classical form of cervical cancer. The term invasive carcinoma includes a wide spectrum of lesions, ranging from a very minute localized type of cancer that is invisible to the naked eye (microcar-cinoma) to advanced bulky disease that is widely disseminated. Just where carcinoma in situ ends and the earliest forms of invasive carcinoma begin continues to be a subject of dispute and debate among cytopathologists. From the standpoint of diagnosis, treatment, and prognosis, each of these borderline cases must be given individual consideration.

Gross Findings

It is important to remember that it is possible to have invasive cervical cancer without a clinically obvious lesion. Usually, however, the lesions are visible and palpable and can be classified in one of three groups:

1. Ulcerative. The substance of the cervix is locally eroded.

2. Exophytic. The lesion arises from the surface of the cervix in the form of a projection-the so-called cauliflower type.

3. Nodular. This produces a picture of uneven induration concentrating particularly beneath the surface of the cervix.

Combinations of all three types are likely to occur.

Microscopic Findings

Virtually all cervical cancer is of the epidermoid variety, usually moderately differentiated. Adenocarcinoma is uncommon. When it does occur, it usually arises from the endocervical canal. Combinations of these two varieties of lesions are classified as adenoacanthomas.

Staging Of Lesions

Systems have been devised that group cancer of the cervix according to the stage of the disease as determined by clinical findings. It is important to emphasize that such grouping is a clinical classification and is uninfluenced by subsequent pathologic or surgical findings. Thus on the basis of any lesion found by the physician at the time of his first examination, a patient can be assigned to one of five stages. Decisions regarding treatment and estimation of prognosis hinge on such a classification. It has, therefore, a real practical significance.

For years the most widely used staging system was the League of Nations classification. This has been amended by adding a fifth stage (Stage 0) to the four already existing in order to accord proper recognition to the newer concept of carcinoma in situ and is now called the international classification (Fig. 52).

Fig. 52. International classification of cancer of the cervix.

Stage 0 Carcinoma in situ

Stage I The cancer is strictly confined to the cervix

Stage II The cancer extends beyond the cervix but has not reached the pelvic wall; the vagina is involved but not the lower third

Stage III The cancer has reached the pelvic wall (no '"cancer-free" space is found between the tumor and the pelvic wall); the lower third of the vagina is invaded

Stage IV The cancer appears to involve the bladder or rectum, or both, or has extended beyond the limits previously described (distant metastases may or may not be present)

It is not pertinent here to dwell on the refinements, pitfalls, and problems of clinical staging of cancer of the cervix. However, the practitioner should be aware of this sort of classification since it provides a general guide to the potential curability of a given lesion.

Pathways Of Spread

The pathways of spread of cervical carcinoma are shown in Fig. 53.