Anogenital dysplasia – Diagnostics – Overview of Information and Clinical Research

Anogenital dysplasia involves changes in cells of the genital or anal regions that are not cancer but may, in some cases, progress to cancer over time. Understanding when and how to get tested can help catch these changes early, when they are most manageable.

Introduction: Who Should Undergo Diagnostics and When

Most people with anogenital dysplasia experience no symptoms at all, which makes knowing when to seek diagnostic testing especially important. Because the condition often develops silently, certain groups of people are encouraged to undergo screening even if they feel perfectly healthy.^[1]

You should consider diagnostic testing if you belong to any of the higher-risk groups. These include people living with HIV (human immunodeficiency virus), men who have sex with men, transgender women, anyone with a history of HPV (human papillomavirus) infection in the genital or anal area, and individuals who have had previous cervical, vaginal, vulvar, or anal cancers or dysplasia. People who have received organ transplants or take medications that weaken the immune system, such as treatments for rheumatoid arthritis or inflammatory bowel disease, should also seek evaluation.^[3]^[5]

Even if you don’t fall into a high-risk category, it’s advisable to seek medical attention if you notice certain symptoms. These warning signs include abnormal discharge, bleeding that occurs between periods or after sexual contact, persistent itching in the genital or anal area, a lump or small growth you can feel, or pain lasting longer than three to four weeks.^[1] While these symptoms can also result from common conditions like hemorrhoids or infections, they warrant medical evaluation to rule out dysplasia.

Screening is particularly important because most anogenital dysplasia goes away on its own without treatment. However, when dysplasia does not resolve naturally, it has the potential to develop into cancer. Early detection through diagnostic testing allows healthcare providers to monitor changes and intervene if necessary, potentially preventing cancer from developing altogether.^[1]

⚠️ Important

If you have a weakened immune system due to HIV, organ transplant medications, or other conditions, you should discuss regular screening with your healthcare provider even without symptoms. These individuals have a significantly higher risk of developing dysplasia and of that dysplasia progressing to cancer.

Diagnostic Methods for Identifying Anogenital Dysplasia

The diagnosis of anogenital dysplasia typically begins with a simple screening test called a Pap smear or Pap test. For anal dysplasia, healthcare providers perform an anal Pap smear by inserting a small cotton swab into the entrance of the anus and rotating it for a few seconds to collect surface cells from the anal canal. This collected sample is then sent to a laboratory where specialists examine the cells under a microscope to look for abnormalities and check for the presence of HPV.^[6]^[8]

For genital dysplasia affecting the cervix, vagina, or vulva, providers use similar Pap smear techniques during a pelvic examination. A speculum is inserted to allow access to these areas, and cells are collected with a small brush or swab. The process is quick and causes minimal discomfort for most people.^[1]

When a Pap smear reveals abnormal cells, the next diagnostic step is usually a more detailed examination called high-resolution anoscopy, or HRA. This procedure allows doctors to look directly at the affected area with magnification. During HRA, the healthcare provider applies a numbing gel and then inserts a thin, hollow tube called an anoscope approximately three inches into the anal canal. A special microscope called a colposcope, which stays outside the body, is positioned to magnify and examine the tissue inside.^[7]^[25]

To make abnormal areas easier to see during HRA, providers apply liquid stains to the tissue. These stains cause cells with abnormalities to appear different from healthy cells. The entire procedure typically takes about 15 minutes and does not require the bowel preparation needed for procedures like colonoscopy. Most patients can have HRA performed in a clinic setting without sedation.^[5]^[8]

For examining genital dysplasia, healthcare providers use a similar procedure called colposcopy. During colposcopy, the provider uses a speculum to view the cervix, vagina, or vulva and applies a vinegar-like solution that makes abnormal cells more visible under magnification. This allows for careful inspection of any suspicious areas.^[18]

If abnormal areas are identified during HRA or colposcopy, the next step is typically a biopsy. During a biopsy, the healthcare provider removes a tiny piece of tissue, usually only about 2 millimeters in size, from the abnormal area. This tissue sample is sent to a pathology laboratory where it is examined under a microscope to determine the grade of dysplasia. The biopsy helps distinguish between low-grade dysplasia, which often resolves on its own, and high-grade dysplasia, which may require treatment to prevent progression to cancer.^[7]^[25]

After a biopsy, you may experience some occasional bleeding or discomfort for one to two days, usually during bowel movements if the biopsy was taken from the anal area. Healthcare providers typically give written instructions for post-biopsy care to help manage any discomfort and watch for signs of complications.^[7]

The biopsy report will classify the findings into categories. Healthcare providers may refer to these findings using different terminology, but they generally fall into similar groups. Low-grade squamous intraepithelial lesion, or LSIL (also called grade 1 AIN), describes cells that look relatively similar to healthy cells and are unlikely to become cancer. High-grade squamous intraepithelial lesion, or HSIL (also called grade 2 or grade 3 AIN), describes cells that look more abnormal and have a greater chance of progressing to cancer if left untreated.^[3]^[14]

⚠️ Important

High-resolution anoscopy and colposcopy require specialized training and equipment. Not all healthcare facilities offer these services. If your Pap smear shows abnormalities, your provider may refer you to a specialized dysplasia clinic where trained experts can perform these detailed examinations and biopsies.

Diagnostics for Clinical Trial Qualification

Clinical trials testing new treatments for anogenital dysplasia use specific diagnostic tests as standard criteria to determine whether someone is eligible to participate. These tests help researchers ensure that trial participants have the condition being studied and can safely receive the experimental treatment being tested.^[1]

Most clinical trials for anogenital dysplasia require participants to have documented evidence of dysplasia through biopsy results. The biopsy must typically show high-grade dysplasia, as this is the form most likely to benefit from intervention and most at risk of progressing to cancer. Trial enrollment criteria often specify the exact grade and location of dysplasia required for participation.^[13]

Clinical trials also commonly require confirmation through high-resolution anoscopy or colposcopy before enrollment. These procedures document the size, location, and appearance of abnormal areas, providing baseline measurements that researchers use to evaluate whether treatments are working. During the trial, participants typically undergo repeat HRA or colposcopy at scheduled intervals to monitor changes in the dysplasia.^[13]

Beyond tests that confirm dysplasia itself, clinical trials often require additional diagnostic assessments to ensure participant safety. These may include blood tests to check immune system function, particularly measurement of CD4 cell counts in people living with HIV. Trials may also require tests to confirm the presence and type of HPV infection, as certain treatment approaches target specific HPV strains.^[15]

Some clinical trials test topical medications applied directly to areas of dysplasia. For these studies, precise mapping of dysplasia locations through HRA or colposcopy is essential. Researchers photograph or document the exact areas of abnormality before treatment begins, then use the same imaging techniques to assess whether the treatment has reduced or eliminated the dysplasia.^[15]

Trials may exclude people with certain biopsy findings, such as those whose tissue samples show cells that have already progressed beyond dysplasia to invasive cancer. For this reason, pathology review of biopsy specimens is a critical qualification step. Some trials even require a second pathologist to review the biopsy slides to confirm the diagnosis before enrollment.^[13]

Throughout a clinical trial, participants undergo regular diagnostic monitoring. This typically includes repeat Pap smears every few months, repeat HRA or colposcopy examinations, and repeat biopsies of previously abnormal areas. These ongoing diagnostic tests help researchers track whether the experimental treatment is effective at reducing or eliminating dysplasia and whether any new areas of dysplasia develop during the study period.^[13]

Prognosis and Survival Rate

Prognosis

The outlook for people with anogenital dysplasia depends largely on the grade of dysplasia and the individual’s overall health, particularly immune system function. Most cases of low-grade dysplasia resolve spontaneously without any treatment. These lower-grade abnormalities rarely progress to cancer and often disappear as the body’s immune system clears the HPV infection that caused them.^[3]

High-grade dysplasia has a different trajectory. While some cases may still resolve on their own, high-grade lesions are less likely to disappear without intervention and carry a higher risk of progressing to cancer. However, the progression from high-grade dysplasia to cancer is not inevitable or rapid. When high-grade dysplasia is detected and treated early, the prognosis is generally very good, as treatment can effectively remove abnormal cells before they become cancerous.^[3]

For people living with HIV or those with weakened immune systems from other causes, the prognosis requires more careful consideration. These individuals are more likely to develop dysplasia, more likely to have persistent disease that does not resolve on its own, and face a higher risk of progression to cancer. Even after successful treatment, people with compromised immune function experience higher rates of recurrence, meaning the dysplasia returns months or years later. This makes ongoing monitoring particularly important for this population.^[3]

The chance that dysplasia will progress to cancer varies considerably based on individual circumstances. Factors affecting prognosis include older age, smoking history, the specific type of HPV infection present, and the degree of immune suppression. People with multiple risk factors face higher odds of progression than those with fewer risk factors.^[10]

Survival Rate

Studies examining the progression rate from high-grade anal dysplasia to anal cancer have found that approximately 3% to 14% of people with high-grade dysplasia eventually develop anal cancer. This means that the vast majority of people with high-grade dysplasia do not develop cancer, especially when they receive appropriate monitoring and treatment.^[3]^[14]

However, progression rates are significantly higher in certain populations. Research has shown that about half of people who have both HIV infection and anal dysplasia may eventually develop anal cancer if the dysplasia is not treated. This underscores the importance of regular screening and prompt treatment for individuals living with HIV.^[3]^[14]

It’s important to note that anogenital dysplasia itself is not a life-threatening condition. The concern is the potential for progression to cancer. When dysplasia is detected and monitored appropriately, healthcare providers can intervene before cancer develops. This preventive approach means that most people with dysplasia never develop cancer and can expect a normal life expectancy.^[1]

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