Cancer of the cervix uteri originates in one of three structures: I. The squamous epithelium covering the vaginal aspect of the cervix; II. The cylindrical cells lining the cervical canal; III. The epithelial cells of the cervical glands. The first variety is called squamous-cell carcinoma of the cervix. The second and third varieties are called adeno-carcinoma of the cervix.

The early appearance of the disease, the gross form assumed by the cancer, the direction of growth, and the clinical course depend upon the place of origin. In the late stages of the disease, characterized by extensive destruction of tissue, all forms appear alike.

I. Cancer of the vaginal aspect of the cervix (squamous-cell carcinoma) very often begins in a benign erosion of an old laceration. The early stages of transition from the benign to the malignant condition are not apparent to the unaided senses, and can be recognized only by the microscope. Later a superficial ulceration is developed, or the cancer may assume the polypoid or vegetating form, and become readily recognized by the unaided senses.

Fig. 114.—Cancer of the vaginal aspect of the cervix.

It will be remembered that true ulceration as a benign condition is very rare on the cervix uteri. The erosion of a laceration is in no sense an ulceration. An ulceration of the cervix, therefore, should always excite the gravest suspicion. The polypoid or vegetating growths vary very much in size. They are sometimes very exuberant, forming large cauliflower-like masses filling the upper part of the vagina ([Fig. 114]). In other cases they are small warty growths or rounded protuberances about the size of a pea. The disease usually spreads to the mucous membrane of the vagina. Less often it extends to the cervical canal and to the body of the uterus.

II. When the cancer begins in the mucous membrane of the cervical canal (adeno-carcinoma), extensive destruction of tissue may take place before any appearance of the disease is observed at the external os ([Fig. 115]). This is most likely to occur in those cases in which there is not present a bilateral laceration of the cervix with eversion of the mucous membrane. In some cases the whole of the cervix is destroyed, leaving only a shell, the lower portion of which is the vaginal aspect of the cervix.

Fig. 115.—Cancer of the cervical canal, with metastasis to the vagina.

When the cervix is lacerated and the mucous membrane of the canal is exposed, the disease is more early apparent, and we may then observe the malignant ulceration of the exposed mucous membrane or the presence on it of cancerous outgrowths. This form of cancer of the cervix uteri is more likely to extend upward to the endometrium than is the form first described.