How to test a genital lesion for Human Papillomavirus (HPV)?

From the Guidelines

To test a genital lesion for HPV, a healthcare provider should perform a visual examination followed by a biopsy or swab of the suspicious area, as the most recent and highest quality study does not support the routine use of type-specific HPV nucleic acid tests in the diagnosis or management of visible genital warts 1. The most common test is a DNA test where cells are collected from the lesion using a small brush or swab.

• For women, this is often done during a Pap test,
• while for men, the sample is taken directly from visible lesions. PCR (polymerase chain reaction) testing is typically used to detect HPV DNA in the sample, which can identify both the presence of HPV and specific high-risk strains. For visible warts, a healthcare provider might apply acetic acid (vinegar solution) to the area, which causes HPV-infected tissue to turn white, helping to identify lesions that might not be clearly visible. In some cases, a biopsy may be necessary, where a small piece of tissue is removed and examined under a microscope. HPV testing is important because certain high-risk strains can lead to cancer, while low-risk strains typically cause genital warts. Early detection allows for appropriate treatment and monitoring, especially for high-risk HPV types that could progress to cancer if left undetected, as supported by the guidelines for cervical cytology screening that incorporate the use of HPV detection as an important adjunct 1.

The performance of cervical cytology has undergone several refinements since its introduction, including the introduction of liquid-based, thin-layer preparations, which facilitates the application of molecular diagnostic techniques to the detection of high-risk HPV genotypes 1. However, the routine use of acetic acid soaks and examination with light and magnification, as a screening test, to detect "subclinical" or "acetowhite" genital warts is not recommended, as acetowhitening is not a specific test for HPV infection 1. In special situations, experienced clinicians find this test useful for identification of flat genital warts 1.

It is also important to note that HPV testing is not recommended for women under age 30, women with low- or high-grade intraepithelial lesions, or those with a history of sexually transmitted diseases, because all are likely to be infected with HPV 1. Women who have a negative cytologic examination as well as a negative HPV test need to undergo cervical cytology testing only at 3-year intervals instead of the currently recommended 1-year interval 1.

Overall, the diagnosis and management of genital lesions for HPV should be based on the most recent and highest quality evidence, taking into account the patient's age, medical history, and risk factors, as well as the availability and cost of HPV testing 1.

From the Research

Testing for HPV in Genital Lesions

To test a genital lesion for HPV, the following methods can be used:

• Colposcopy: a procedure that uses a special microscope to examine the cervix, vagina, and vulva for abnormal cell growth 2
• High-resolution anoscopy (HRA): a technique used to visualize the anal canal and detect abnormal cell growth, similar to colposcopy 3
• Visual inspection with acetic acid (VIA) and Lugol's iodine (VILI): methods that use a vinegar solution and an iodine solution to highlight abnormal cell growth on the cervix 4
• HPV testing: a laboratory test that detects the presence of HPV DNA in a sample of cells taken from the cervix or other genital areas 5

Colposcopy Procedure

Colposcopy is an office-based procedure that involves:

• Applying a dilute acetic acid solution to the cervix to highlight abnormal cell growth
• Using a colposcope to examine the cervix under magnification
• Taking a biopsy of any suspicious lesions for further examination 2
• Using Lugol's iodine as a contrast agent to help visualize abnormal cell growth 6

High-Resolution Anoscopy (HRA) Procedure

HRA is a technique used to visualize the anal canal and detect abnormal cell growth, similar to colposcopy. It involves:

• Using a colposcope with acetic acid and Lugol's iodine to visualize the anal canal
• Taking a biopsy of any suspicious lesions for further examination 3

HPV Testing

HPV testing is a laboratory test that detects the presence of HPV DNA in a sample of cells taken from the cervix or other genital areas. It can be used to:

• Screen for HPV infection in individuals with abnormal cell growth or genital lesions
• Monitor the effectiveness of treatment for HPV-related diseases 5