A colposcopy is a detailed examined of the cervix by a gynaecologist, usually to investigate the source of an abnormal cervical smear result.
A colposcopy is a diagnostic procedure in which a colposcope (a specialised camera) is utilized to examine an illuminated, magnified view of the cervix, the tissue of the vagina, and vulva. Many premalignant lesions and malignant lesions in these areas have discernible characteristics which can be detected with a thorough colposcopic examination. The enlarged view provided by the colposcope allows the colposcopist to visually distinguish normal from abnormal appearing tissue and take directed biopsies for further pathological examination.
The prevention of cervical cancer through the early detection and treatment of precancerous lesions is the principal goal of colposcopy.
Indications for colposcopy
In September 2001, the American Society for Colposcopy and Cervical Pathology held a conference to create "Guidelines for the Management of Cytological Abnormalities and Cervical Cancer Precursors." Recommendations contained in this report form the basis for many current evaluation and treatment decisions. Most women undergo a colposcopic examination to further investigate an abnormality on their pap smears. Other indications for a woman to have a colposcopy include assessment of diethylstilbestrol (DES) exposure in utero, HIV infection or immunosuppression, or an abnormal appearing cervix noted at the time of the pap smear.
During the initial evaluation, a medical history is obtained, including gravidity (number of prior pregnancies), parity (number of prior deliveries), last menstrual period, contraception use, prior abnormal pap smear results, allergies, significant past medical history, other medications, prior cervical procedures, and smoking history. A pregnancy test is usually done before the procedure is performed. The procedure is fully described to the patient, questions are asked and answered, and she then signs a consent form.
The colposcope is the most important piece of equipment used during the procedure. The colposcope basically functions as a lighted binocular microscope, which magnifies the view of the cervix, vagina and vulvar surface and helps to identify visible clues suggestive of abnormal tissue. Low power (2x to 6) may be used to obtain a general impression of the surface architecture. Medium (8x to 15x) and high (15x to 25x) powers are utilized to evaluate the vagina and cervix. The higher powers are often necessary to identify certain vascular patterns which may indicate the presence of more advanced precancerous or cancerous lesions. Various light filters are available to highlight different aspects of the surface of the cervix. Acetic acid solution and iodine solution (Lugol's or Schiller's) are applied to the surface to improve visualization of abnormal areas.
Colposcopy is performed with the patient in the dorsal lithotomy position (woman lying with her legs in stirrups and her buttocks close to the lower edge of the table). A speculum is placed in the vagina after the vulva is examined for any suspicious lesions. Three percent acetic acid is applied to the cervix using cotton swabs. The transformation zone is a critical area on the cervix where many precancerous and cancerous lesions most often arise. The ability to see the transformation zone and the entire extent of any lesion visualized determines whether an adequate colposcopic examination is attainable. Areas of the cervix which turn white after the application of acetic acid or have an abnormal vascular pattern are often considered for biopsy. If no lesions are visible, an iodine solution may be applied to the cervix to help highlight areas of abnormality. After a complete examination, the colposcopist determines the areas with the highest degree of visible abnormality and obtains biopsies from these areas using a long biopsy instrument. Some doctors consider anesthesia unnecessary, however, many colposcopists now recommend and use a topical anesthetic such as lidocaine or a cervical block to diminish patient discomfort, particularly if many biopsy samples are taken. Following the biopsies, an endocervical currettage (ECC) is often done. The ECC utilizes a long straight currette to scrape the inside of the cervical canal. The ECC should never be done on a pregnant woman. Monsel's solution is applied with large cotton swabs to the surface of the cervix to control bleeding. This solution looks like mustard and becomes black in color when exposed to blood. As this material is expelled, women can expect to have a thin coffee-ground like discharge for up to several days after the procedure.
Significant complications from a colposcopy are not common, but may include bleeding, infection at the biopsy site or endometrium, and failure to identify the lesion. Monsel's solution and silver nitrate interfere with interpretation of biopsy specimen, so these substances should not be applied until all biopsies have been taken.
Some patients experience varying levels of pain during the procedure and biopsy. While medical journals usually describe such pain as "minor", many women report the discomfort to be significant. Women with a history of sexual abuse may find the colposcopy procedure traumatic.
Adequate follow up is critical to the success of this procedure. Human Papilloma Virus (HPV) is a common infection which is the underlying cause for most cervical dysplasia. Women should be counselled on the benefits of safe sex for reducing their risks of contracting and spreading the HPV virus. A new vaccination against HPV was approved June 8, 2006 by the US Food and Drug Administration after being tested for five years on 20,541 girls from age 16 to 26. The vaccine is indicated for prevention of cervical cancer, precancerous and dysplastic lesions and genital warts caused by HPT types 6, 11, 16 and 18. Adequate widespread vaccination may reduce the need for colposcopic examinations in the future.
Smoking predisposes women to developing cervical abnormalities. A smoking cessation program should be part of the treatment plan for women who smoke.
Without proper treatment, minor abnormalities may develop into cancerous lesions. Various treatment modalities exist for the treatment of significant lesions. The most common treatments are cryotherapy, loop electrical excision procedure (LEEP), and laser ablation.