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Medical Author:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• What is colposcopy?
• Why is colposcopy done?
• How is colposcopy done?
• What special tests are done during colposcopy?
• Acetic acid wash
• Use of color filters
• Biopsy of the cervix
• Based on the colposcopy results, what is the approach to treating cervical abnormalities?
• What should one expect from each of the treatments for cervical abnormalities?
• Carbon dioxide laser photoablation
• Cryocautery
• Loop electrosurgical excision procedure
• Cold knife cone biopsy
• Hysterectomy
• Colposcopy At A Glance
• Patient Comments: Colposcopy - Diagnosis
• Find a local Obstetrician-Gynecologist in your town
• Colposcopy Index

What special tests are done during colposcopy?

Three special tests are done during colposcopy: acetic acid wash, use of color filters, and sampling (biopsy) of tissues of the cervix.

Acetic acid wash

After the cervix is studied with the colposcope, the cervix is washed with a chemical called acetic acid, which is diluted 3% to 5%. The acetic acid washes away mucus and allows abnormal areas to be seen more easily with the colposcope. Moreover, the acetic acid stains the abnormal areas white. The areas that stain white after the acetic acid wash are called "acetowhite lesions." Sometimes, however, normal areas can also stain white, but these areas have vague or faint borders. In contrast, significant abnormalities, such as genital warts, pre-cancers (dysplasia), and cancers, generally produce acetowhite areas with distinct and clear boundaries.

Sometimes staining with a dilute iodine solution (known as Lugol's solution or Schiller's solution) is also performed to further examine for abnormalities. Normal cells will generally take up the iodine stain (and turn brown) in a uniform manner, whereas severe precancers and cancerous areas will not.

Use of color filters

Another aspect of colposcopy involves the use of color filters. The filters help the physician examine tiny blood vessels (capillaries) in the area of the squamocolumnar junction. Blue or green filtered light can cause abnormal capillaries to become more obvious, usually inside an acetowhite area.

Normal capillaries are slender and spaced out evenly. In contrast, abnormal capillaries can appear as red spots (thickened capillaries seen on end) or can produce a pattern resembling hexagonal floor tiles. The worse the cervical disease, the thicker and more widely spaced out are the capillaries. The abnormal capillary pattern ranges from mild, as with pre-cancer (dysplasia), to severe, as with established cancer. Thus, when cancer eventually develops, capillaries take on odd shapes, like punctuation marks.