The ovaries are organs in the female reproductive system. The National Cancer Institute (NCI) says they are located in the pelvis, one on each side of the uterus. Each ovary is about the size and shape of an almond. They produce eggs and female hormones.
MD Anderson Cancer Center reports there are more than 30 different types of ovarian tumors, which are categorized according to the cell type from which they start.
Some are benign (noncancerous) and don’t spread beyond the ovary. Malignant (cancerous) tumors can spread to other parts of the body. There are three types of ovarian tumor cells.
One is epithelial cell tumors. Web MD says these tumors start from the cells on the surface of the ovaries.
The National Ovarian Cancer Coalition (NOCC) says most epithelial ovarian tumors are benign. When cancerous, epithelial tumors are carcinomas.
These are the most common and most dangerous of all types of ovarian cancers. Unfortunately, almost 70 percent of women with the common epithelial ovarian cancer are not diagnosed until the disease is advanced in stage.
Another type is germ cell tumors. NCI says these tumors begin in the reproductive cells of the body. Most are benign but some can be cancerous.
The most common ovarian germ cell tumor is called dysgerminoma. Ovarian germ cell tumors usually occur in teenage girls or young women and most often affect just one ovary.
NOCC reports today 90 percent of patients with ovarian germ cell malignancies can be cured and their fertility preserved.
And the third type is stromal tumors. NOCC and the Ovarian Cancer National Alliance say ovarian stromal tumors develop from connective tissue cells that hold the ovary together and those that produce the female hormones, estrogen and progesterone. These tumors are quite rare.
According to Web MD, doctors aren’t sure what causes ovarian cancer. However, they have identified several risk factors. These include age (specifically women who have gone through menopause), smoking, obesity, not having children or not breastfeeding, fertility drugs, hormone replacement therapy, family or personal history of ovarian, breast or colorectal cancer.