Obstetrics and Gynecology at Boston Medical Center: comprehensive women’s health care

Obstetrics & Gynecology

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Anal Dysplasia and Anal Cancer

Anal Dysplasia is abnormal cells (or a lesion) in the lining (skin) of the anal canal. It can be low-grade (mild) or high-grade (moderate to severe). Some low-grade lesions may progress (get worse) to high-grade lesions. High-grade lesions are very common. High-grade lesions can progress to cancer. About 1/1,000 of high-grade lesions per year will progress to cancer.

Anal dysplasia is caused by the human papillomavirus (HPV).

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What is HPV?

HPV is the most common sexually transmitted virus. Around 75-80% of sexually active people have been infected with HPV, and this is much higher in people with HIV.  There are over 40 different HPV types that may infect the genital (private) area.

Learn more about HPV-related diseases.

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Frequently Asked Questions (FAQs) for Anal Cancer and Anal Dysplasia

  1. Who is at risk of getting anal cancer?
  2. What happens during an evaluation for anal dysplasia and cancer?
  3. How can I protect myself against HPV infection and anal dysplasia?

1. Who is at risk of getting anal cancer?

A risk factor is anything that affects your chance of getting a disease such as cancer. People at increased risk for anal dysplasia/cancer may have the following risk factors:

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2. What happens during an evaluation for anal dysplasia and cancer?

History:  Your provider will ask you about how you are doing, your health habits, past illnesses and treatments.
-Digital Exam: An exam of the anus and rectum. Your provider inserts a lubricated, gloved finger into the anus and lower part of the rectum to feel for lumps or anything else that seems unusual.

Anal Pap test (or anal cytology): A moist swab, like a Q-Tip ® is passed into the anal canal and cells that come off on the swab are examined under a microscope. This procedure helps to check for abnormal cells in the anus. It takes about 10 seconds and causes minimal discomfort.

It takes about 2 weeks to get the Anal Pap Test results back.

Anal Pap Test Results

Benign or Normal: There are no abnormal changes in the cells and no treatment is needed. The anal Pap test should be repeated in 6 to 24 months, depending on what risk factors you have.

HRA with Possible Biopsy:

The provider will use a plastic instrument called an anoscope and look at the anal canal with a special microscope called a colposcope. If an abnormal area is seen, then a very small piece of anal tissue may be removed (biopsy) and sent to a specialist (pathologist) to check for signs of cancer. Anyone with an abnormal anal Pap test should have an HRA with possible biopsy to examine the anal canal.  The procedure takes about 15 minutes.

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3. How can I protect myself against HPV infection and anal dysplasia?

Although anal dysplasia can be treated successfully, people with HPV are at high risk of having it come back. While important to your health, HPV therapy does not protect against anal dysplasia/cancer. It is important to follow up with regular check-ups.

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Online Resources

For more information on anal cancer, please download the (PDF) brochures for Anal Dysplasia/Cancer and Infrared Coagulation.

For more information, please contact:


For information about open clinical trials:



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Two office locations for Obstetrics & Gynecology at Boston Medical Center:

Doctors Office Building
11th Floor
720 Harrison Avenue
Boston, MA 02118
Call: 617.414.2000
Fax: 617.638.7852

Yawkey Ambulatory Care Center
4th Floor
850 Harrison Avenue
Boston, MA 02118
Call: 617.414.2000
Fax: 617.414.7212

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Call: 800.682.2862

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