Ovarian cancer is a malignant ovarian neoplasm (an abnormal growth located on the ovaries).
Classification
Ovarian cancer is classified according to the histology of the tumor. Lesions differ significantly in clinical features, management, and prognosis:
* Epithelial ovarian tumors are the most common and prototypic ovarian cancers. They are thought to originate from the ovarian surface lining, including the serous cystadenocarcinoma, and the mucinous cystadenocarcinoma.
* Stromal ovarian cancer includes lesions that are hormonally active such as the estrogen-producing granulosa cell tumor and the virilizing arrhenoblastoma.
* Germ cell cancer originates from dysplastic germ material and tends to occur in young women and girls. Lesions include the dysgerminoma, a form of the choriocarcinoma, and the malignant form of the teratoma.
* Other lesions include metastasis to the ovary, for instance from breast cancer. Krukenberg cancer is ovarian cancer originating from gastrointestinal cancer.
Staging
Ovarian cancer staging is by the FIGO staging system and uses information obtained after surgery, which should include a total abdominal hysterectomy, removal of (usually) both ovaries and fallopian tubes, (usually) the omentum, and pelvic (peritoneal) washings for cytology. The AJCC stage is the same as the FIGO stage.
* Stage I – limited to one or both ovaries
o IA – involves one ovary; capsule intact; no tumor on ovarian surface; no malignant cells in ascites or peritoneal washings
o IB – involves both ovaries; capsule intact; no tumor on ovarian surface; negative washings
o IC – tumor limited to ovaries with any of the following: capsule ruptured, tumor on ovarian surface, positive washings
* Stage II – pelvic extension or implants
o IIA – extension or implants onto uterus or fallopian tube; negative washings
o IIB – extension or implants onto other pelvic structures; negative washings
o IIC – pelvic extension or implants with positive peritoneal washings
* Stage III – microscopic peritoneal implants outside of the pelvis; or limited to the pelvis with extension to the small bowel or omen tum
o IIIA – microscopic peritoneal metastases beyond pelvis
o IIIB – macroscopic peritoneal metastases beyond pelvis less than 2cm in size
o IIIC – peritoneal metastases beyond pelvis > 2 cm or lymph node metastases
* Stage IV – distant metastases
Para-aortic lymph node metastases are considered regional lymph nodes (Stage IIIC).
