What Is an Endometriosis Biopsy? Purpose, Procedure and Accuracy

What Is an Endometriosis Biopsy?

An endometriosis biopsy is a medical test used to examine a small sample of tissue to check for signs of endometriosis, a chronic condition in which tissue similar to the uterine lining grows outside the uterus. This tissue responds to hormonal changes during the menstrual cycle and can lead to inflammation, scar tissue and severe pain.

This biopsy is usually performed during laparoscopy, a minimally invasive surgical procedure that allows doctors to directly view the pelvic organs and collect samples from abnormal areas. It looks for endometrial-like glands, stromal cells or associated inflammation outside the uterus. Identifying these features helps confirm a diagnosis, especially when symptoms are severe or fertility concerns are present.

Why Is an Endometriosis Biopsy Done?

A biopsy is done to support or clarify a suspected diagnosis when symptoms persist.

Your doctor may consider an endometriosis biopsy if you have:

• Persistent pelvic pain
• Painful or heavy periods
• Pain during intercourse
• Difficulty conceiving
• Inconclusive imaging results
• Symptoms that do not improve with medical treatment

Because endometriosis occurs outside the uterus, tissue must be taken from areas such as the pelvic lining, ovaries or ligaments where lesions are seen.

When Might a Biopsy Be Recommended for Endometriosis?

A biopsy may be recommended for endometriosis when earlier, non-invasive tests have not provided clear answers. It is usually considered after initial assessments are complete and symptoms such as pelvic pain or cycle-related discomfort remain unexplained.

The test may be suggested if ultrasound or MRI findings are unclear or do not fully account for ongoing symptoms, if symptoms continue despite treatment or if there is a need to rule out other conditions with similar signs. In some situations, a biopsy can also help clarify findings before deciding on further treatment options.

An endometriosis biopsy is not a first-line diagnostic test. It is typically performed only when laparoscopy is already being carried out and when examining tissue more closely may help guide diagnosis and ongoing care.

How Is an Endometriosis Biopsy Performed?

An endometriosis biopsy is done during laparoscopic surgery, while you are under anaesthesia, so you won’t feel anything during the procedure. The biopsy happens as part of the surgery, not as a separate test.

During laparoscopy, the doctor makes a few small cuts in the abdomen and inserts a thin camera to look inside the pelvis. This allows them to check the uterus, ovaries and nearby areas for signs of endometriosis. If any spots look unusual, very small pieces of tissue are taken from those areas.

The tissue samples are sent to a laboratory, where they are examined under a microscope. This helps confirm whether the tissue shows features of endometriosis. If suitable, the doctors may also remove or treat visible lesions during the same surgery, which can help avoid the need for another procedure later.

Does an Endometriosis Biopsy Cause Pain?

It is not usually painful because the biopsy is performed while you’re under anaesthesia. The tissue sample is taken as part of the surgery, so there’s no separate sensation from the biopsy itself.

Afterwards, some discomfort is normal. You might feel sore around the abdomen, notice bloating or feel more tired than usual. Shoulder pain can also happen for a short time because of the gas used to inflate the abdomen during laparoscopy.

These effects usually ease over a few days and improve with rest and simple pain relief. Your doctor will let you know what to expect and when things should start feeling back to normal.

How Accurate Is an Endometriosis Biopsy?

When a biopsy is taken during laparoscopy, it is one of the most reliable ways to confirm endometriosis. Examining tissue under a microscope helps doctors clearly identify changes linked to the condition.

That said, a single biopsy does not always tell the whole story. In some cases, the tissue sample may not capture all affected areas, even if endometriosis is present elsewhere. This is why what the doctor sees during the surgery plays an important role.

In practice, diagnosis is based on a combination of biopsy results, surgical findings, symptoms and overall clinical judgement rather than one test alone.

What Happens After the Results?

Results help guide further diagnostic or treatment decisions. Depending on findings, next steps may include:

• Monitoring symptoms
• Medical management
• Hormonal treatment
• Pain management strategies
• Referral to a specialist
• Reviewing fertility-related concerns
• Adjusting or continuing current treatment plans

Conclusion

An endometriosis biopsy can sometimes help clarify what may be behind certain symptoms. When tissue is taken during laparoscopy, doctors are able to look more closely at areas that appear unusual and get a better sense of what is going on.

For someone dealing with persistent pain or fertility concerns, it helps to know that biopsy results are not viewed on their own. They are considered together with symptoms, scan findings and clinical judgement.

This combined approach helps guide treatment decisions and next steps in care. A clear diagnosis allows for more targeted, personalised management.