Introduction:
Any abnormal changes that happen to the cells in the body are called dysplasia. Anal dysplasia is a precancerous condition and not cancer. They are usually seen in people between the ages of 50 and 80. Anal dysplasia is also known as anal intraepithelial neoplasia (AIN) I, II, and III, Bowen's disease, and squamous cell carcinoma in situ.
What Is Anal Dysplasia?
Anal dysplasia is when abnormal changes occur in the cells of the anus. With time, the abnormal cells multiply and form tumors, eventually spreading to other body areas and developing into anal cancer.
How Does Anal Dysplasia Develop?
Anal dysplasia begins in the mucosa, in the inner lining of the anal canal, where the healthy cells of the mucosa turn into abnormal cells. The anal canal extends from the anus to the rectum. The rectum is the last straight portion of the large intestine. The anus is the opening of the rectum outside the body. These changes usually happen where the anal canal meets the rectum; they can also develop from the skin outside the anus (perianal skin).
Anal dysplasia is categorized into low-grade squamous intraepithelial lesions (SIL) and high-grade squamous intraepithelial lesions. In low-grade SIL, the abnormal cells usually look healthy and will go away without any treatment. These cells rarely become cancerous. In high-grade SIL, the abnormal cells require treatment for them to resolve. There are chances that these cells can turn into cancer cells.
What Causes Anal Dysplasia?
All variants of human papillomavirus (HPV) can cause anal dysplasia. Other causative factors include cigarette smoking, human immunodeficiency virus (HIV), a weak immune system due to certain medications or autoimmune disorders, and a history of anal intercourse, even if condoms are used. The virus pools in the base of the penis or vagina and spread to the perianal region during sexual intercourse. HPV infections can also spread from areas not covered by condoms.
What Are the Symptoms Seen in Anal Dysplasia?
Anal dysplasia is asymptomatic in most cases. However, some symptoms can develop. They include a change in bowel movements, either less or more, excess straining during bowel movements, pain in the anal region, anal itching, bleeding from the anus, and feeling of a mass or lump in the anus. Sometimes anal warts and mucous discharge from the anus will also be noted.
Who Is at More Risk for Anal Dysplasia?
People who are at increased risk of anal dysplasia include older people, organ transplant recipients, a history of precancerous growth in the anus or anal wart, weak immune systems due to some medications or underlying autoimmune conditions, HIV infection, people who have frequent unprotected anal intercourse, and people who have had HPV-related cancers like vulvar cancer, cervical cancer or vaginally cancer.
How Is Anal Dysplasia Diagnosed?
The healthcare provider will take a detailed medical history and determine whether the patient has HPV or HIV infection. Other tests to diagnose anal dysplasia include:
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Physical Examination - The doctor will check for any lumps or masses in the anal region.
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Anal Pap Smear - This test is similar to pap smear tests and is done by inserting a swab into the anus to collect the cells. Pathologists examine the cells for any precancerous or cancerous condition.
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Anoscopy - An anoscope is a small tube coated with an anesthetic gel and inserted into the anus to check for abnormal cells. Sometimes a high-resolution anoscopy (HRA) is also done. In HRA, the doctor spreads certain substances like vinegar into swabs inserted into the anal canal to highlight the abnormal or precancerous area. The presence of vinegar can turn the abnormal cells into white, and specific vascular markings will be formed.
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Biopsy - If the initial tests show the presence of precancerous cells, a biopsy will be performed. A biopsy is done by removing tissues from the anal canal.
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Computed Tomography (CT) Scans - In case cancer is diagnosed, CT scans are done to understand the extent of the spread of cancer.
How Is Anal Dysplasia Treated?
The treatment for anal dysplasia depends on its type and extent of spread. A patient with low-grade SIL will be periodically monitored to note any changes or whether the dysplasia worsens, and the treatment options for patients with high-grade SIL include:
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Chromoendoscopy - An endoscope is used to stain the abnormal tissue in this procedure. During the examination of the anus, the abnormal tissues are destroyed. By destroying the cells, the chances of the cells developing into anal cancer will be low.
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Laser Treatment - Here, the abnormal tissue is removed with the help of lasers.
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Electrocautery or Infrared coagulator: In this procedure, intense beams of light or heat are given to the affected area, destroying abnormal cells while protecting the unaffected region. However, recurrence is seen in HIV patients, so they should be closely monitored and followed up with anal pap smears at an interval of three months.
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Trichloroacetic Acid: It is a kind of acetic acid soaked in a cotton pad; this cotton is placed on the affected areas, which helps treat the affected cells. It is done as three or four treatments over a few weeks.
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Surgery - Surgery is done to remove the affected tissue.
How Can Anal Dysplasia Be Prevented?
The main way to prevent anal dysplasia is by reducing the chance of getting infected by HPV infection. Some ways to reduce the risk of anal dysplasia include:
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Since HPV infections are one of the main causes of anal dysplasia, vaccinating against HPV reduces the chances of developing anal dysplasia.
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HPV is a sexually transmitted disease (STD), so people who participate in anal intercourse or have multiple sex partners should try using condoms for intercourse to prevent an infection.
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If a person is sexually active and has frequent unprotected sex, it is essential to have regular STD checks.
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Smoking increases the chances of anal dysplasia. Hence it is important to stop smoking to prevent the risk of the condition.
Conclusion:
Anal dysplasia is a precancerous condition that occurs when healthy cells of the anus undergo changes and become abnormal. If left untreated, the abnormal cells will likely develop into cancer cells. So, it is important to note symptoms like anal itching, abnormal mass in the anus region, and anal bleeding and seek medical care. The symptoms can be diagnosed by physical examination and various techniques like anoscopy. Once the condition is diagnosed, various treatment modalities are performed to destroy the abnormal cells.
