Ovarian Tumor Types

Ovarian cancer can develop in the ovaries, the fallopian tubes or the peritoneum, which is the tissue surrounding the organs in the abdominal cavity. Cancers of the fallopian tubes and peritoneum are regarded as ovarian cancers because they require the same therapies.

Not all tumors that occur in the ovaries or surrounding tissues are cancerous. Certain types of ovarian tumors are slow-growing and are more responsive to treatment.

Ovarian tumors are classified according to the type of cells they develop in.

If you have an ovarian tumor, your physicians will perform a surgery to determine what kind of cells it consists of, and whether those cells are malignant or benign.

Epithelial tumors

Most ovarian tumors are epithelial tumors. They develop in epithelial cells, which form the outermost layer of ovarian tissue. There are three different types of epithelial tumors.

Benign tumors

The majority of epithelial tumors are benign. This means they are not cancerous and will not spread. Surgical removal of benign epithelial tumors is straightforward, and patients don’t need further treatment.

Tumors of low malignant potential

Some epithelial tumors grow slowly. While tumors of low malignant potential are not benign and have the ability to become cancerous, they are also unlikely to invade the surrounding tissue outside the ovary. Like benign tumors, these tumors can be removed through surgery.

Malignant tumors

Malignant epithelial tumors are less common than benign epithelial tumors, but they account for 85 to 95 percent of ovarian cancers. They grow more rapidly and have a high potential to metastasize to other areas of the body.

Patients with malignant epithelial tumors are treated with surgery as well as chemotherapy and rarely with radiation to control the spread of the cancer.

Germ cell tumors

Germ cell tumors occur in the egg cells inside the ovaries. They are rare, making up only 2 percent of ovarian cancers. Patients with germ cell tumors often respond well to treatment, which usually involves removal of the affected ovary.

Ovarian stromal tumors

Ovarian stromal tumors account for only 1 percent of ovarian tumors. They develop in stromal tissue, which produces the hormones estrogen and progesterone.