There are many different ovarian cancer types, which are identified by the kind of cell where the cancer originates. Each type of ovarian cancer has a range of subtypes, leading to more than 30 different types of ovarian cancer overall.
The most common ovarian cancer types
Ovarian tumors most commonly develop in the epithelial cells, which are the cells that make up the outer layer of the ovaries. Epithelial tumors can be benign, or they may be classified as “borderline” (slow-growing with a low potential for becoming cancerous) or “malignant” (cancerous). Malignant cancers can also be categorized as low-grade, or more indolent cancers, and high-grade, or more rapidly growing cancers.
While most ovarian cancers come from the epithelium, the other main types of cells in the ovaries where cancer originates are the germ cells and stromal cells. However, only around 3% of ovarian cancers develop in these cells.
Epithelial ovarian tumors
Cancerous epithelial tumors are the most common type of ovarian cancer, accounting for 85% to 90% of all malignant ovarian tumors. Epithelial ovarian carcinomas are broken down into several subtypes based on specific features of the cells, and these subtypes include:
- Serous carcinoma
- Clear cell carcinoma
- Mucinous carcinoma
- Endometrioid carcinoma
- Malignant Brenner’s Tumor
Serous carcinomas are the most common subtype, accounting for more than 50% of epithelial carcinomas. These epithelial carcinoma types are broken down even further by being given a grade (based on how the cancerous tissue looks compared to normal tissue and on how fast the cancer grows).
Ovarian germ cell tumors
Germ cells are the cells that form the ova or eggs. The majority of germ cell tumors are benign, but some are cancerous. Cancerous ovarian germ cell cancers are subcategorized as teratomas, dysgerminomas, endodermal sinus tumors and choriocarcinomas, or they can even be a mix of more than one subtype.
Ovarian stromal tumors
Only about 1% of ovarian cancer develops in the stromal cells, which are the connective tissue cells that produce the female hormones estrogen and progesterone. Malignant stromal tumor subtypes include granulosa cell tumors, granulosa-theca tumors and Sertoli-Leydig cell tumors; these ovarian cancer types are typically found at an early stage.
Less common ovarian cancer types
Some of the rarer types of ovarian cancer include various sarcomas and malignant cysts. While most ovarian cysts are benign, they can sometimes become cancerous. Ovarian sarcomas develop in the connective tissues of the ovaries and include carcinosarcomas, adenosarcomas, leiomyosarcomas and fibrosarcomas.
Ovarian cancer treatment at Moffitt
Moffitt Cancer Center’s gynecological oncology program provides treatment for all types of ovarian cancer. To learn more about ovarian cancer types, or to consult with our ovarian cancer treatment team, call 1-888-663-3488 or complete a new patient registration form online. Referrals are not required.
Medically reviewed by Robert Wenham, MD, Chair, Gynecologic Oncology Program