There are two major types of uterine cancer:
Adenocarcinoma. This makes up more than 80% of uterine cancers. It develops from cells in the lining of the uterus called the endometrium. This cancer is also commonly called uterine cancer. A common type of endometrial adenocarcinoma is called endometrioid carcinoma, and treatment varies depending on the grade of the tumor, how far it goes into the uterus, and the stage or extent of disease (see Stages and Grades). A less common type is called endometrial serous carcinoma, and this form is treated in a fashion similar to ovarian cancer which is also commonly of the serous type.
Sarcoma. This type of uterine cancer develops in the supporting tissues of the uterine glands or in the myometrium, which is the uterine muscle. Sarcoma accounts for about 2% to 4% of uterine cancers. Sarcomas are treated differently than adenocarcinomas in most situations. Types of uterine cancers with some elements of sarcoma include leiomyosarcoma, endometrial stromal sarcoma or carcinosarcoma.
The 2 main types of cancer of the uterus are:
Endometrial carcinomas can be divided into different types based on how the cells look under the microscope (histologic types). These include:
The most common type of adenocarcinoma is known as endometrioid cancer. Endometrioid cancers are made up of cells in glands that look much like the normal uterine lining (endometrium). Some of these cancers contain squamous cells (squamous cells are flat, thin cells that can be found on the outer surface of the cervix), as well as glandular cells. A cancer with both types of cells is called an adenocarcinoma with squamous differentiation. If, under the microscope, the glandular cells look cancerous but the squamous cells don′t, the tumor may be called an adenoacanthoma. If both the squamous cells and the glandular cells look malignant (cancerous), these tumors can be called adenosquamous (or mixed cell) carcinomas. There are other variants (or sub-types) of endometrioid cancers, such as secretory carcinoma, ciliated carcinoma, and villoglandular adenocarcinoma.
Clear-cell carcinoma, mucinous adenocarcinoma, and papillary serous adenocarcinoma.are less common types of endometrial adenocarcinomas. These types tend to be more aggressive than most uterine cancers. They tend to grow quickly and often have spread outside the uterus at the time of diagnosis.