Types of Ovarian Cancers

Ovarian cancer includes different types, which can behave differently and require different treatments. Most ovarian cancers start in the epithelium, which is the outer surface layer of the ovary. Some less common types can start in the tissues that support the ovaries or in the egg cells.

Here are some of the main types of ovarian cancer:

Common Epithelial Ovarian Cancers: These are the most frequently diagnosed types.

• High-grade serous carcinoma (HGSC): This is the most common type of epithelial ovarian cancer and is often fast-growing.
• High-grade endometrioid carcinoma: This is another common type of epithelial ovarian cancer and shares some features with cancers of the lining of the uterus.

Less Common Ovarian Cancers (LCOCs) or Less Common Ovarian Histologies (LCOHs): These are rarer types of ovarian cancer.

• Low-grade serous carcinoma: This is a less common type of epithelial ovarian cancer that tends to grow more slowly.
• Low-grade endometrioid carcinoma: This is another less common epithelial type and is a slower-growing form of endometrioid carcinoma.
• Carcinosarcoma (also called malignant mixed Mullerian tumors): This is a rare type of epithelial ovarian cancer containing a mix of cancer cell types.
• Clear cell carcinoma: This is a less common type of epithelial ovarian cancer where the inside of the cancer cells looks clear under a microscope.
• Mucinous carcinoma: This is a rare type of epithelial ovarian cancer that often contains mucus-producing cells.
• Borderline epithelial tumor (also called low malignant potential tumors): This type of tumor starts in the epithelial cells but grows slowly and is less likely to invade other tissues.

Less Common Non-Epithelial Ovarian Cancers: These start in different types of cells in the ovary.

• Malignant sex-cord stromal tumors: These rare cancers develop from the supportive tissues of the ovaries.
• Malignant germ cell tumors: These rare cancers originate from the reproductive (egg) cells of the ovary. For example, Granulosa Cell Tumors

Knowing the specific type of ovarian cancer is important for planning the most effective treatment.