After ovarian low malignant potential tumor has been diagnosed, tests are done to find out if abnormal cells have spread within the ovary or to other parts of the body.

The process used to find out whether abnormal cells have spread within the ovary or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. Certain tests or procedures are used for staging. Staging laparotomy (a surgical incision made in the wall of the abdomen to remove ovarian tissue) may be used. Most patients are diagnosed with stage I disease.

The following stages are used for ovarian low malignant potential tumor:

Stage I

In stage I, the tumor is found in one or both ovaries or fallopian tubes. Stage I is divided into stage IA, stage IB, and stage IC.

• Stage IA: The tumor is found inside a single ovary or fallopian tube.
• Stage IB: The tumor is found inside both ovaries or fallopian tubes.
• Stage IC: The tumor is found inside one or both ovaries or fallopian tubes and one of the following is true:
  • tumor cells are found on the outside surface of one or both ovaries or fallopian tubes; or
  • the capsule (outer covering) of the ovary ruptured (broke open) before or during surgery; or
  • tumor cells are found in the fluid of the peritoneal cavity (the body cavity that contains most of the organs in the abdomen) or in washings of the peritoneum (tissue lining the peritoneal cavity).

Stage II

In stage II, the tumor is found in one or both ovaries or fallopian tubes and has spread into other areas of the pelvis, or primary peritoneal cancer is found within the pelvis. Stage II is divided into stage IIA and stage IIB.

• Stage IIA: The tumor has spread from where it first formed to the uterus and/or the fallopian tubes and/or the ovaries.
• Stage IIB: The tumor has spread from the ovary or fallopian tube to organs in the peritoneal cavity (the space that contains the abdominal organs).

Stage III

In stage III, the tumor is found in one or both ovaries or fallopian tubes, or is primary peritoneal cancer, and has spread outside the pelvis to other parts of the abdomen and/or to nearby lymph nodes. Stage III is divided into stage IIIA, stage IIIB, and stage IIIC.

• In stage IIIA, one of the following is true:
  • The tumor has spread to lymph nodes in the area outside or behind the peritoneum only; or
  • Tumor cells that can be seen only with a microscope have spread to the surface of the peritoneum outside the pelvis, such as the omentum (a fold of the peritoneum that surrounds the stomach and other organs in the abdomen). The tumor may have spread to nearby lymph nodes.
• Stage IIIB: The tumor has spread to the peritoneum outside the pelvis, such as the omentum, and the tumor in the peritoneum is 2 centimeters or smaller. The tumor may have spread to lymph nodes behind the peritoneum.
• Stage IIIC: The tumor has spread to the peritoneum outside the pelvis, such as the omentum, and the tumor in the peritoneum is larger than 2 centimeters. The tumor may have spread to lymph nodes behind the peritoneum or to the surface of the liver or spleen.

Stage IV

In stage IV, tumor cells have spread beyond the abdomen to other parts of the body. Stage IV is divided into stage IVA and stage IVB.

• Stage IVA: Tumor cells are found in extra fluid that builds up around the lungs.
• Stage IVB: The tumor has spread to organs and tissues outside the abdomen, including lymph nodes in the groin.

Ovarian low malignant potential tumors can recur (come back) after they have been treated.

The tumors may come back in the other ovary or in other parts of the body.