Borderline tumor of the ovary

Borderline ovarian tumours are abnormal cells that form in the tissue covering the ovary. They are not cancer and are usually cured with surgery.


Around 15 out of 100 ovarian tumours (15%) are borderline tumours. They are also described as atypical proliferative tumours and used to be called tumours of low malignant potential.

They are different to ovarian cancer because they don't grow into the supportive tissue of the ovary (the stroma). They tend to grow slowly and in a more controlled way than cancer cells.

Borderline tumours usually affect women aged between 20 and 40. They are usually diagnosed at an early stage, when the abnormal cells are still within the ovary.

Occasionally some abnormal cells break away from the tumour and settle elsewhere in the body, usually the abdomen. Very rarely, these cells start to grow into the underlying tissue.

The main treatment for borderline tumours is surgery. Most women are cured and have no further problems. There is a small risk of the tumour coming back. Very rarely, the borderline tumour cells change into cancer cells.



Small borderline tumours don't usually cause symptoms. Doctors might find the tumour while you're having tests for something else.

Larger or more advanced borderline tumours might cause symptoms.

Symptoms can include:

pain or a feeling of pressure in the tummy area (pelvis or abdomen)
a swollen abdomen
pain during or after sex
vaginal bleeding not related to your period.

Staging shows the size of the tumour and whether it has spread. Doctors use the same staging system for borderline tumours as for ovarian cancer. There are 4 stages, from 1 to 4:
stage 1 is the earliest stage where the borderline tumour is within the ovary
stage 2 generally means the abnormal cells have spread within the pelvis, for example to the womb, fallopian tubes, bladder or the back passage (rectum)
stage 3 means the cells have spread outside the pelvis into the abdominal cavity
stage 4 is the most advanced. It means the cells have spread to another part of the body, such as the lungs
Surgery is usually the only treatment you need for a borderline ovarian tumour. The surgery you have depends on:

where the tumour is and whether it has spread
whether you want to have children
For many women, surgery involves removing:

both ovaries and fallopian tubes
the womb, including the cervix
This operation is called a total abdominal hysterectomy (TAH) and bilateral salpingo oophorectomy (BSO).



If the tumour is only within the ovary, and you plan on having children in the future, your doctor (gynaecologist or gynaecological oncologist) may remove just the affected ovary and fallopian tube.

During the operation your doctor will closely look at the inside of your pelvis and abdomen, and take samples. This is to check for any signs that the tumour has spread.

They might also remove part of the fatty tissue close to your ovaries called the omentum.

If you have a mucinous type of borderline ovarian tumour, your doctor might also remove your appendix. This is because mucinous tumours can sometimes start in the appendix and then spread to the ovary.

Most women are cured with surgery. If a borderline tumour does come back, you have more surgery. Your doctor will talk to you about the type of surgery you need.

We have information about having a hysterectomy and your recovery afterwards in the ovarian cancer section. Remember this section is about ovarian cancer, and so some of the information may not be relevant.



Dr. A. Kavallaris
Gynecologist Oncologist