A cold knife cone biopsy (conization) is surgery to remove a sample of abnormal tissue from the cervix. The cervix is the lower part of the uterus (womb) that opens at the top of the vagina. Abnormal changes in the cells on the surface of the cervix is called cervical dysplasia.
This procedure is done in the hospital. You will be placed under general anestheisa (asleep and pain-free), or you will be given medicines to help you relax and feel sleepy.
You will lie on a table and place your feet in stirrups to position your pelvis for examination. The doctor will place an instrument (speculum) into your vagina to better see the cervix.
A small cone-shaped sample of tissue is removed from the cervix . It is examined under a microscope for signs of cancer. This biopsy may also be a treatment if the doctor removes all of the diseased tissue.
How to prepare for the test
As with any procedure that is done under anesthesia, you will probably need to fast for 6 - 8 hours. You must sign an informed consent form. The procedure is done on the same day (outpatient) and a hospital stay is usually not needed.
How the test will feel
After the procedure, you may have some cramping or discomfort for a week or so. For about 4 - 6 weeks avoid:
Douching (you should never do this in any case)
For 2 - 3 weeks after the procedure, you may have discharge that is:
Why the test is performed
Cold knife cone biopsy is done to detect cervical cancer or early changes that lead to cancer. A cold knife biopsy is done if a test called colposcopy cannot find the cause of an abnormal Pap smear.
Cold knife cone biopsy may also be used to treat:
Moderate to severe types of abnormal cell changes (called CIN II or CIN III)
A normal result means there are no precancerous or cancerous cells in the cervix.
What abnormal results mean
Most often, abnormal results mean that there are precancerous or cancerous cells in the cervix. These changes are called cervical intraepithelial neoplasia (CIN). The changes are divided into three groups:
CIN I -- mild dysplasia
CIN II -- moderate to marked dysplasia
CIN III -- severe dysplasia to carcinoma in situ
Abnormal results may also be due to cervical cancer.
What the risks are
Risks of cold knife cone biopsy include:
Incompetent cervix (which may lead to premature delivery)
Scarring of the cervix (which may cause painful periods, premature delivery, and difficulty getting pregnant)
Cold knife cone biopsy may also make it difficult for your health care provider to interpret abnormal Pap smear results.
American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 99: Management of abnormal cervical cytology and histology. Obstet Gynecol. 2008;112:1419-1444.
Martin-Hirsch PPL, Paraskevaidis E, Bryant A, Dickinson HO, Keep SL. Surgery for cervical intraepithelial neoplasia. Cochrane Database of Systematic Reviews 2010, Issue 6. Art. No.: CD001318.
Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.