Norm of Pap Smear
Results are reported according to the Bethseda System in a descriptive statement regarding the adequacy of the sample, followed by a descriptive diagnosis. Abnormalities are described as benign, low-grade squamous, high-grade squamous, glandular, or severe dysplasia with carcinoma in situ.
Terms used to describe abnormal cells include the following:
May Also Be Called
|Atypical squamous cells of undetermined significance (ASCUS)||May indicate need for further diagnostic evaluation|
|Dysplasia, mild, moderate, or severe||Appearance of cells is abnormal; no invasion of healthy tissue; cells may develop into early cervical cancer SIL, CIN 3||Mild: low-grade SIL, CIN 1
Moderate: high-grade SIL,
CIN 2 Severe: high-grade
|Squamous intraepithelial lesion (SIL), low grade or high grade||Abnormal appearance of cervical surface cells, which appear thin and flat|
|Cervical intraepithelial neoplasia (CIN)||Presence of abnormal cell growth in cervical surface cells; may be further described with numbers 1 to 3 to indicate how much of cervix contains abnormal cells|
|Carcinoma in situ||Presence of preinvasive cancer cells on surface of cervix||High-grade SIL, CIN 3|
Class I Normal
Class II Probably normal
Class III Doubtful (may be malignant)
Class IV Probably malignant
Class V Malignant
Abnormal cells indicative of endocrine disorders, cancer (uterine), endometriosis, lymphogranuloma venereum, tumors (cervical), and vaginal adenosis or inflammation that could lead to cancer.
Normal cervical cells.
Usage of Pap Smear
This test is primarily used in the early detection of cervical and vaginal carcinomas and scrapings from the uterus. The smear technique can also used to detect cancerous cells of the breast (aspiration of mammary gland tissue), lung (bronchial brushing and washing from bronchoscopy or coughed-up sputum), stomach (aspirated gastric secretions), and renal system (urine sediment). It is indicated as routine screening and for work-up of disorders of reproduction function.
Description of Pap Smear
The Pap smear, the most widely used cancer-screening tool, is a cytologic examination of desquamated epithelial tissue to differentiate normal from anaplastic cells. Both a traditional slide method and a newer liquid method are described here. In the traditional method, one prepares the smears by scraping or aspirating cells from the tissue to be examined (that is, the cervix) and fixing them on glass slides, using ether and 95% ethyl alcohol (ethanol) solution. Slides are then dried, stained, and examined under a microscope by a pathologist or cytotechnologist. In the newer liquid Pap method, the tissue scrapings are placed in liquid to remove mucus and debris, which can interfere with the view through the microscope. Many studies have found that most human cervical cancers harbor types of high-risk human papillomavirus (HPV). For this reason, studies are being conducted to evaluate whether circulating HPV DNA in the plasma can serve as a marker for cervical cancer. (See Human papillomavirus in situ hybridization—Specimen.)
Professional Considerations of Pap Smear
Consent form NOT required.
- See Client and Family Teaching.
- Interview the client; record age, date of last menstrual period, prior history of abnormal Pap smear results, and pregnancy status.
- Obtain a glass slide, a sterile Ayre spatula (for the ectocervix), a cytobrush (for the endocervix), a tongue blade, a pipette, a sterile cotton swab, sterile gloves, ether/ 95% alcohol solution (1:1), spray fixative, a graphite pencil, and a speculum. Using the graphite pencil, label the frosted ends of the slide with the client's name and the collection site. For liquid procedure, obtain ThinPrep.
- The client should disrobe below the waist.
- Position the client recumbent on a gynecologic examination table in the lithotomy position, and drape for comfort and privacy.
- Liquid Pap Method: Follow the steps below, substituting “transfer of the specimen to the ThinPrep Pap container” to “transfer of the specimen to a slide.”
- Note: Fixative must be applied to the slide before any drying of the specimen occurs. If a two-step specimen is taken, fixative should be applied after each step. Remove excess mucus by placing a 2- × 2-inch gauze pad over the cervix and gently peeling it away after a few seconds.
- Endocervical Smear:
- a. Aspirate endocervical secretions from the cervical os as through a pipette. Spread the secretions onto a glass slide. Dip or spray the slide with the prepared fixative and dry it.
- b. Insert a cytobrush into the cervical os and rotate it 360 degrees, using one continuous motion. Smear the scrapings onto a glass slide, using a single continuous stroke to avoid traumatizing the cells. Fix immediately as described above.
- Ectocervical Scraping: Using a wooden tongue blade or the blunt side of a wooden Ayre spatula inserted into the cervical os, rotate or scrape the entire surface at the squamocolumnar junction. Remove the tongue blade and smear onto a glass slide. Fix immediately as described above.
- Cervical Scraping: Insert the pointed edge of a wooden Ayre spatula into the cervical os and rotate the spatula 360 degrees. Spread the cervical scrapings on a glass slide, fix it with an ether/95% ethyl alcohol solution, and dry the slide. A Cervex-Brush sampling device may be used, and it is recommended to be rotated a full 180 degrees to improve the sampling for abnormal cervical cells.
- Vaginal Pool: Using the blunt side of a wooden Ayre spatula, scrape the vaginal floor behind the cervix. Spread the vaginal pool secretions on a glass slide, spray or soak them in fixative, and dry the slide. Vaginal fluid is obtained for suspected endometrial cancer or for a hormonal evaluation.
- Vulva Smear: Using the blunt side of a wooden Ayre spatula, directly scrape the vulvar lesion. Spread the scraping on a glass slide and fix it immediately with spray fixative.
- On the laboratory requisition, write the client's age; the reason for the study; the date of the last menstrual period; any chemotherapy or hormonal medications; and history, including any previous abnormal Pap smears and treatment for cancer or abnormal vaginal bleeding.
- Send the slides to the cytology laboratory.
Client and Family Teaching
- For clients of childbearing age, test should be done 10–20 days after the first day of the last menstrual period.
- Do NOT douche for 18–72 hours before the procedure.
- It is customary practice for the client to be informed of the results, either positive or negative. The method of information exchange needs to be arranged with the client's physician.
- 1 week is needed for result.
- Further testing may be needed, including a repeat Pap, endometrial biopsy, or colposcopy. This decision will be made when the results of the test are received.
- Pap smears should be performed either yearly after 21 years of age or 3 years after becoming sexually active, whichever is earliest in the client's history. If the client is sexually active, has a family history of cervical or uterine cancer, has venereal disease, or has a mother who took diethylstilbestrol during pregnancy, a Pap smear should be performed before 18 years of age and yearly thereafter.
Recommended Cervical Pap Frequency Age (Years)
Regular (Traditional) Pap
Liquid-Based Pap (ThinPrep by Quest Diagnostics)
|<21||Begin annual screenings at 3 years after becoming sexually active||Same|
|21–29||Annually||Every 2–3 years|
|30–70||If last three tests were normal, decrease frequency to every 2–3 years||Every 2–3 years|
|>70||Consider discontinuation of screening if last three tests were normal AND if there were no abnormal results in last 10 years||Same|
|After subtotal hysterectomy||Same as above||Same as above|
|After total hysterectomy because of invasive cervical disease||Every 3 months × 2 years, then every 6 months|
|After total hysterectomy not necessitated by cancer or precancerous conditions||Not needed unless client has risk factors for cervical cancer||Same|
Factors That Affect Results
- Smears that dry before fixative is applied cannot be properly interpreted.
- Do not lubricate the speculum; such lubrication distorts cells.
- Use of formalin as a fixative invalidates the results.
- Water or lubricant on the specimen can distort the cells.
- A smear taken any time other than in the midmenstrual cycle can result in abnormal findings. The best time for a cervical cytology study is 5–6 days after menses.
- Inadequate specimens may require retesting.
- Tetracycline or digitalis preparations can affect the look of squamous epithelium.
- Blood, mucus, or pus on the slide makes accurate specimen interpretation difficult. The presence of infection in the cervical area may contribute to the absence of endocervical cells.
- Cells that are damaged from excessive manipulation during collection may be interpreted as atypical.
- False-positive Pap smear results requiring a repeat test in 6–12 weeks, as is standard, may be avoided if a culture for Chlamydia and Neisseria gonorrhoeae and wet-mount slides are examined at the time of the examination.
- False-negative results can be minimized by obtaining double scrapings and smear cultures.
- See also Pap smear, Ultrafast and fine-needle aspiration.
- Precancerous cervical cells often take up to 5 years to become cancerous. The American Cancer Society revised its recommendations for frequency of cervical cancer screening via Pap smear to reflect studies that have shown that less frequent testing only slightly increases the risk of missing precancerous conditions, but reduces the likelihood of detecting and subsequently overtreating benign cervical conditions.
- Many studies have found that most human cervical cancers harbor the high-risk human papillomavirus (HPV) types. For this reason, studies are being conducted to evaluate whether circulating HPV DNA in the plasma can serve as a marker for cervical cancer.
Consensus Guidelines of the American Society for Colposcopy and Cervical Pathology (ASCCP) Recommended Follow-up for Abnormal Pap Smears
|Atypical squamous cells (ASCs) of undetermined significance (ASCUS)||Two repeat cytology tests
Immediate colposcopy with loop electrosurgical excision procedure (LEEP) (see Colposcopy)
DNA testing for high-risk types of human papillomavirus (preferred choice, if method used for Pap testing was liquid-based cytology); see Human papillomavirus in situ hybridization—Specimen
|Finding cannot exclude high-grade squamous intraepithelial lesion (HSIL; ASC-H)||Immediate colposcopy with loop electrosurgical excision procedure (LEEP)|
|Low-grade squamous intraepithelial lesion or atypical glandular cells|