Endometriosis, a condition that mainly affects women, is associated with the growth of tissue similar to the endometrium — the lining of the uterus — outside of the uterus. It can cause severe pain, and the potential scarring of internal organs as well as infertility.

A common and accurate method of diagnosing endometriosis is through a biopsy.

What is a biopsy?

A biopsy involves surgically removing a small piece of tissue, in this case tissue from a suspected endometrial lesion, to be examined in a laboratory. For endometriosis, this surgery may be carried out during a laparoscopy.

A laparoscopy involves the doctor making small incisions in the abdomen of a patient, normally under general anesthesia. He or she then inserts a laparoscope, a flexible thin tube with a light and camera, into an incision to identify the lesion. The laparoscope can then be used to safely guide surgical instruments, inserted through a separate incision, to the lesion.

Other methods include deep excision surgery, which may help treat the symptoms of endometriosis as well as help to diagnose the condition. Deep excision surgery removes the lesion, possibly relieving symptoms, while leaving intact surrounding healthy tissue. The lesion is then sent for examination in a laboratory.

Another approach uses a punch biopsy, which removes only a small piece of the lesion to be examined in the lab. Several punch biopsies may need to be taken to test different lesions or different parts of a lesion.

Biopsy results

In the laboratory, the tissue is examined under a microscope to identify the presence of certain structures. In particular, endometrial glands and stroma are commonly seen in endometrial lesions. Endometrial glands are tube-like structures that change in shape during the menstrual cycle in response to the hormone estrogen. The stroma is a tissue rich in blood vessels to support the glands.

If endometriosis has been present in the patient for some time before a biopsy is taken, the stroma may be difficult to identify visually due to scarring. In these cases, CD10 antibody staining can help to identify the tissue. The CD10 antibody is a protein that will recognize and bind to the CD10 protein, which is present in endometrial stroma, including that in places outside the uterus. If the CD10 protein is present, the antibody will stick to the tissue so that it can be visualized under the microscope. A stain in abnormal locations generally indicates that the patient has endometriosis.


A biopsy carried out during laparoscopy is generally a low-risk procedure. However, there is a minor risk of internal bleeding, damage to the organs, or air bubbles entering and blocking blood vessels, an event known as a gas embolus. There is also a risk of the surgery site becoming infected, or bruised or scarred.

Following surgery, patients should contact a medical professional if any of the following symptoms occur: severe pain or fever, nausea or vomiting, increased bleeding, pain or smelly discharge from the surgical site, or abnormal smelly discharge from the vagina.

In some cases, the lesions may be difficult to access or involve several organs. This may require the involvement of several specialist surgeons to reduce the risk of complications during surgery.


Endometriosis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.