What is a cone biopsy?

A cone biopsy is surgery to remove abnormal cells from the cervix. The cervix is the neck-shaped opening at the lower, narrow part of the uterus that connects the uterus to the vagina. During the procedure, a cone-shaped piece of tissue is removed from the cervix and sent to a lab for analysis. 

Cone biopsy may be used to treat cervical disease, such as cervical dysplasia or early cervical cancer. Cone biopsy is also used to diagnose the cause of moderate to severe cell abnormalities. 

Your doctor may recommend a cone biopsy after other gynecologic screening tests, such as a Pap test, colposcopy, or a cervical biopsy, detect pre-cancer or early cervical cancer. A cone biopsy may be the only treatment needed to cure your condition or biopsy results can help guide future treatments.

Cone biopsy is only one method used to treat cervical abnormalities. Other treatments with fewer risks may be available. Ask your doctor about all your treatment options and consider getting a second opinion before deciding on cone biopsy. 

Why is a cone biopsy performed?

Your doctor may recommend a cone biopsy under these circumstances: 

  • A Pap test or cervical biopsy finds moderate to severe cervical cell changes.
  • You need treatment of precancerous cells or very early cervical cancer.
  • Your doctor is unable to see or access abnormal cervical tissue with colposcopy.
  • Your doctor needs to diagnose the cause of the abnormal cell changes. Your doctor may also use the results of a cone biopsy to help guide future treatment. 

Who performs a cone biopsy?

An obstetrician-gynecologist (Ob-Gyn) commonly performs cone biopsy. An Ob-Gyn is a doctor who specializes in women’s reproductive health. 

How is a cone biopsy performed?

Your doctor will perform a cone biopsy in a hospital. The procedure, also called cold knife cone biopsy, takes about 15 minutes, but you will be in the hospital for several hours for pre and postoperative care. 

Cone biopsy involves gently inserting a speculum into your vagina to view and access the cervix. A colposcope (a special magnifying glass) may be used to examine the cervix and find the abnormal areas. 

Your doctor will use a scalpel (surgical knife) or laser to remove the abnormal cervical tissue. The amount of tissue removed varies but is usually about 1.5 cm wide and 1 cm deep. A small amount of normal tissue around the abnormal area is also cut out. This ensures all abnormal cells are removed. The specimen is then examined using a microscope.

Types of anesthesia 

Your doctor will perform a cone biopsy using either general anesthesia or regional anesthesia. 

  • General anesthesia is a combination of intravenous (IV) medications and gases that put you in a deep sleep. You are unaware of the procedure and will not feel any pain. \
  • Regional anesthesia is also known as a nerve block. It involves injecting an anesthetic around certain nerves to numb the surgical area. You will likely have sedation with regional anesthesia to keep you relaxed and comfortable.

What to expect the day of your cone biopsy

The day of your surgery, you can generally expect to:

  • Talk with a preoperative nurse. The nurse will perform an exam and ensure that all needed tests are in order. The nurse can also answer questions and will make sure you understand and sign the surgical consent form.
  • Remove all clothing and jewelry and dress in a hospital gown. It is a good idea to leave all jewelry and valuables at home or with a family member. Your care team will give you blankets for modesty and warmth.
  • Talk with the anesthesiologist or nurse anesthetist about your medical history and the type of anesthesia you will have.
  • A surgical team member will start an IV. 
  • The anesthesiologist or nurse anesthetist will start your anesthesia.
  • A tube may be placed in your windpipe to protect and control breathing during general anesthesia. You will not feel or remember this or the surgery as they happen.
  • The surgical team will monitor your vital signs and other critical body functions. This occurs throughout the procedure and during recovery until you are alert, breathing effectively, and your vital signs are stable.