Human Papillomavirus Workup

Updated: Jan 05, 2017
  • Author: Peter A Gearhart, MD; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
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Workup

Approach Considerations

The diagnosis of most cutaneous and external genital warts can be made on clinical examination or with application of acetic acid and biopsy. In the case of genital intraepithelial neoplasia, determining the extent of disease is essential. This involves careful inspection, as well as colposcopy.

Detection of human papillomavirus (HPV) DNA is now approved by the US Food and Drug Administration (FDA) and is valuable as a screening tool in women older than 30 years. Identification of genotypes is available only in research laboratories through the use of DNA hybridization techniques, [54] including Southern blot (highly sensitive but time-consuming), dot blot, and in situ hybridization. Others methods include enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) antibody (Ab) against HPV 16 capsid.

Patients who present with condylomata acuminata do not necessarily need other laboratory studies. Patients who are diagnosed with condylomata are at an increased risk for other sexually transmitted diseases (STDs). Consider testing for chlamydia, gonorrhea, syphilis, hepatitis B, hepatitis C, herpes, and HIV, depending on the clinical situation. These patients need a Papanicolaou (Pap) test of the cervix in accordance with the guidelines of the American College of Obstetricians and Gynecologists.

In general, imaging studies have a limited role in diagnosing HPV infections. Computed tomography (CT) or magnetic resonance imaging (MRI) can be used to determine the extent of spread of cervical carcinoma and extensive anogenital papillomatosis that has spread into the pelvis.

Histologic examination of the vulvar lesions to detect vulvar condyloma is sometimes difficult. Non-HPV conditions, such as vestibular papillomatosis and inflammatory squamous metaplasia, may be difficult to distinguish from condylomata with light microscopy. The pathologist may report microscopic features from a biopsy of the vulva that are suggestive, but not diagnostic, of HPV. When the histologic diagnosis of condyloma is questionable, HPV testing may be useful.

The following are 2015 guidelines on HPV screening and management from a guidance panel cosponsored by the Society of Gynecologic Oncology and the American Society for Colposcopy and Cervical Pathology: [56, 57]

  • A negative high-risk HPV test provides greater reassurance of a low risk of CIN grade 3 or cancer (CIN3+) than a negative cytology result.
  • Because of equivalent or superior effectiveness, primary high-risk HPV screening can be considered an alternative to current US cytology-based cervical cancer screening methods. Cytology alone and co-testing remain the screening options specifically recommended in major guidelines.
  • Based on limited data, triage of high-risk HPV–positive women using a combination of genotyping for HPV 16 and 18 and reflex cytology for women positive for the 12 other high-risk HPV genotypes appears to be a reasonable approach to managing high-risk HPV–positive women.
  • Rescreening after a negative primary high-risk HPV screen should occur no sooner than every 3 years.
  • Primary high-risk HPV screening should not be initiated prior to age 25 years.
  • Although primary HPV screening at age 25-29 years may increase CIN3 detection, further research is needed to determine the effect of increased number of colposcopies, integration with screening before age 25 years, and actual effect on cancer prevention.
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Cytologic Testing

Cervical cytologic testing with the Pap test is the standard screening procedure for cervical neoplasia. Guidelines for cervical cancer screening now include a delay in the initiation of screening and longer intervals between subsequent screens. [1] The initial Pap test should be performed at age 21 years and then every 3 years until age 30 years. The interval can be increased to every 5 years in women 30 years and older who receive a Pap test and co-testing for HPV. An alternative is to continue every 3 years with only a Pap test. [58, 59] Pap test screening can be discontinued after age 65 years if the patient had no previous abnormal Pap test results in the previous 20 years.

Although cervical metaplasia is prevalent among sexually active adolescents, placing them at increased risk for HPV infection, immune system clearance within 1-2 years is common. In addition, invasive cervical cancer is rare among adolescents, and most cervical dysplasias resolve spontaneously. While some studies have suggested women undergoing excisional procedures for cervical dysplasia have an increased risk of preterm births, a 2012 study by Kalliala et all suggests excisional procedures do not appear to increase preterm birth risk. [60] Because adolescents have most of their childbearing years ahead of them, however, delaying cervical cancer screening may be a prudent strategy in this population.

Pap smears should contain samples of cells from the ectocervix, the transformation zone, and the endocervical canal. Perform the test when the patient is not menstruating, so that the cytologic specimen is not occluded with blood. Furthermore, if the patient has a cervicovaginal infection with a mucopurulent vaginal discharge, consider performing the test after the bacterial infection has resolved. If the test must be performed, the discharge should be gently cleared with a saline-moistened cotton swab.

This test may be modified as required to sample any tissues from of the vagina, vulva, or perianal region that are suspicious for intraepithelial neoplasia (see Cervical Cancer). Although this is not an established routine, consider performing annual anal Pap smears on men who are at high risk and who participate in receptive anal intercourse.

Liquid-based Pap smears improve the diagnostic sensitivity of cervical cytology screening. They have the additional benefit of enabling easy testing for human papillomavirus (HPV). Thin Prep and SurePath are 2 methods currently approved by the FDA.

The US Centers for Disease Control (CDC) has specified Clinical Laboratory Improvement Amendments (CLIA) standards for successful participation in a cytology proficiency testing program to ensure the accuracy of interpretation of Pap smears. These guidelines can be found on the CDC Web site under the CLIA section for Gynecologic Cytology Standards. To maintain certification for assessment of Pap smears and other laboratory testing, laboratories in the United States must follow these standards.

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HPV DNA Typing

The two common methods for HPV DNA testing are the Hybrid Capture II (HC II) and the polymerase chain reaction (PCR) enzyme immunosorbent assay. The 2 methods have similarly high sensitivities and are suitable tools for detection of HPV and posttreatment follow-up of cervical intraepithelial neoplasia (CIN).

HPV DNA testing is the preferred approach in the treatment of women whose Pap test results show atypical squamous cells of undetermined significance (ASC-US) whenever liquid-based cytology is used or co-collection is available. HPV DNA testing is also useful in the management of CIN in certain situations. Detailed consensus guidelines for management of abnormal Pap test results and management of CIN are available from the American Society for Colposcopic and Cervical Pathology.

A trial comparing more than 12,000 women who self-collected vaginal HPV specimens with a similar number who underwent cervical cytology screening found that whereas self-collected HPV had a positive predictive value of only 12%, it was 3.4 times more sensitive for detecting CIN II than cervical cytology was and detected 4.2 times more invasive cervical cancers. [61] These findings suggest that self-collected vaginal HPV testing might be a viable surveillance option in communities where cytology screening programs are limited by resources.

Newer HPV tests that are being developed include DNA chip, Linear Array, and cycle sequencing. [62]

The US Food and Drug Administration (FDA) has approved an expanded indication for an HPV DNA test, making it the first such test that can be used alone for primary cervical cancer screening in women aged 25 years or older. The test, the cobas HPV Test, detects DNA from 14 high-risk HPV types in cervical cell samples. A positive test for HPV type 16 or 18 is considered an indication for a colposcopy; a positive test for any of the 12 other high-risk HPV types is considered an indication for a Papanicolaou (Pap) test, in order to determine the need for colposcopy. The cobas HPV Test was first approved in 2011 for use in conjunction with or as a follow-up to a Pap test. [63]

Research supporting the expanded indication included a study of more than 40,000 women aged 25 years or older. The women underwent routine cervical exams, with a colposcopy and cervical tissue biopsy performed on those who had a positive Pap test or whose cervical cells screened positive for HPV, as well as on a subset of women with negative Pap and HPV tests. Comparison of the biopsy results with those from the Pap and cobas HPV tests showed that the HPV test would be effective even when used alone. [63]

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Acetic Acid Test

The acetic acid test can be helpful in the diagnosis of genital warts. In particular, soaking acetic acid into suspicious lesions can enhance the degree of suspicion in lesions without classic features.

The method involves applying a 3-5% acetic acid–moistened gauze pad for 5-10 minutes on suspected lesions of the penis, cervix, labia, or perianal area. Inconspicuous, flat, genital lesions that might be difficult to assess become visible. Dysplastic and neoplastic tissues turn white (acetowhite). False-positive results are common and can result from anything that causes parakeratosis (eg, candidiasis, psoriasis, lichen planus, healing epithelium, sebaceous glands).

The acetic acid test can be used in conjunction with colposcopy to examine cervical lesions. However, this test is reserved only for suspicious lesions and should not be used for routine screening.

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Tissue Biopsy

In general, tissue biopsy can be used to confirm HPV infection if the diagnosis is uncertain, particularly if warts are abnormally pigmented, ulcerated, or indurated.

Patients who appear to have classic condylomata acuminata that fail to respond to therapy should have one of the lesions biopsied. This prevents inappropriate treatment of a lesion unrelated to HPV.

Postmenopausal women who present with lesions resembling condylomata should undergo biopsy before initiation of therapy. These women have a greater chance of having vulvar dysplasia or vulvar cancer than younger women.

Patients who present with typical-appearing condylomata acuminata usually do not need a vulvar biopsy. A biopsy is recommended for the following scenarios:

  • Women with a history of vulvar dysplasia
  • Postmenopausal women
  • Women who fail medical therapy
  • Clinical doubt about the diagnosis

To perform the biopsy, the base of the lesion is injected with 1% lidocaine, and an alligator-mouth biopsy forceps is used to obtain the specimen. Application of silver nitrate to the base of the biopsy site generally controls any bleeding, though in rare cases, suture placement may be required to achieve hemostasis.

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Histologic Findings

Histopathology can elucidate the diagnosis in most cases. Verrucae consist of acanthotic epidermis with papillomatosis, hyperkeratosis, and parakeratosis. Elongated rete ridges may point to the center of the wart, and dermal capillary vessels may be thrombosed. An electron microscope may show viral particles in nuclei. Immunohistochemical staining with the peroxidase-antiperoxidase technique stains cells infected by viral particles.

Virus multiplication is confined to the host cell nucleus. Consequently, infected cells exhibit a high degree of nuclear atypia. The presence of abnormal koilocytes (keratinocytes with pyknotic, deeply blue nuclei surrounded by a halo and clear cytoplasm with a paucity of keratohyaline granules), or koilocytosis, is a characteristic feature of productive HPV infection. Other cytologic markers of HPV infection include acanthosis, dyskeratosis, and multinucleation.

The histology of common cutaneous warts demonstrates marked hyperkeratosis, acanthosis, parakeratosis, and papillomatosis. Three features used to distinguish warts from other papillomas include the presence of koilocytes, vertical columns of parakeratosis, and foci of clumped keratohyaline granules.

The histology of condyloma acuminatum generally demonstrates disruption of the epidermis with hyperkeratosis, coarse keratohyaline granules, and koilocytes in a prominent granular layer. The epidermis or mucosa of flat condylomata demonstrates acanthosis.

The histology of Bowenoid papulosis reveals psoriasiform hyperplasia and hyperkeratosis of the epidermis. Mitotic figures are increased at all epidermal levels. Keratinocytes display enlarged pleomorphic and hyperchromic nuclei.

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