Ovarian Cancer: Types and Histology
Common histologic types of ovarian cancer
Types of Ovarian Cancer
1. Epithelial Carcinoma
Epithelial carcinoma makes up 85% to 90% of ovarian cancers. The main types of epithelial tumors include serous, endometrioid, clear cell, mucinous, mixed tumors, and several rare malignancies, including Brenner tumors.
These types describe how these different ovarian/fallopian tube cancers are classified based on how they look under the microscope.
There can be differences in how these cancers behave and which treatments will work best. The vast majority of epithelial cancers are high-grade serous, meaning they resemble the cells lining the fallopian tube. These cancers are either high-grade serous cancers (HGSC) or low-grade serous carcinoma (LGSC).
High-grade serous cancers (HGSC) make up the vast majority of ovarian/fallopian tube cancer, most of which arise from the fallopian tube. Low-grade serous carcinoma (LGSC) is less common and may arise from the ovaries.
2. Germ Cell Malignancies
This uncommon type of ovarian cancer develops in the egg-producing cells of the ovaries. Germ cell malignancies typically occur in females 10 to 29 years old.
Types of germ cell tumors include dysgerminomas, immature teratoma, endodermal sinus tumors (called EST and yolk sac tumors), and embryonal carcinomas.
3. Sex Cord Stromal Tumors
This rare form of ovarian tumor develops in the connective tissue cells, called granulosa and theca cells, that hold the ovaries together. This tissue sometimes makes the female hormones estrogen and progesterone. Over 90% of these stromal tumors are called granulosa cell tumors, either adult or childhood types.
4. Granulosa Cell Tumors
Granulosa cell tumors may secrete estrogen, resulting in unusual vaginal bleeding at the time of diagnosis. Other types are Sertoli-Leydig cell tumors and steroid cell tumors.