Key Points about Perianal Basal Cell Carcinoma

  • Perianal basal cell carcinoma is a rare type of skin cancer that occurs in or around the anus.
  • Doctors use biopsy, imaging tests and physical exam to diagnose this type of cancer.
  • Treatment for perianal basal cell carcinoma may include surgery, chemotherapy, hormone therapy and/or radiation therapy.


Anal cancer begins in the anus (hole in the buttocks through which stool leaves the body). Perianal basal cell carcinoma is a rare type of skin cancer that develops in the perianal skin, meaning that it develops in or around the anus. In general, basal cell carcinoma is much more common in areas of the skin that are regularly exposed to the sun, such as the arms or face.

Perianal basal cell carcinoma causes

Perianal basal cell carcinoma is caused by mutations (changes) to the DNA of cells of the skin in or around the anus.

Perianal basal cell carcinoma risk factors

The following factors may increase your risk for developing perianal basal cell carcinoma:

  • Being a smoker
  • Being exposed to certain substances, such as arsenic, coal tar, paraffin and some petroleum products
  • Being male
  • Being older
  • Having a compromised immune system
  • Having a light skin complexion or having albinism (absence of skin pigment)
  • Having a personal history of cancer
  • Having basal cell nevus syndrome – also known as nevoid basal cell carcinoma syndrome or Gorlin syndrome
  • Having human papillomavirus (HPV) infection
  • Having undergone psoralens and ultraviolet light (PUVA) treatment for psoriasis
  • Having undergone radiation therapy

Perianal basal cell carcinoma symptoms

Signs and symptoms of perianal basal cell carcinoma may include:

  • Flat, firm, yellow or pale areas of skin that may resemble a scar
  • Open sores that won’t heal or that keep coming back
  • Raised red patches of skin that may be itchy
  • Small, pink or red, shiny bumps that can have brown, blue or black areas

Perianal basal cell carcinoma diagnosis

Your oncologist may use one or more of the following tests to diagnose this cancer:

  • Physical exam – your doctor will perform a complete physical exam, including asking questions about your health history, symptoms and related risk factors.
  • Computerized tomography (CT) scan – this type of imaging test provides a 3-D image of the inside of the body that your doctor can use to determine any cancer present.
  • Biopsy – in this test, your doctor removes a biopsy (small tissue sample) from the suspicious area. This sample is sent to the laboratory, where a specialist closely checks the biopsy for abnormalities.
  • Magnetic resonance imaging (MRI) – this type of imaging test uses high-powered magnets to create detailed images of the inside of your body. Your doctor can closely examine these images to look for any areas that could indicate cancer.

Perianal basal cell carcinoma treatments

Depending on your personal health history, the extent of your perianal basal cell carcinoma and other factors, your oncologist may recommend one or more of the following treatment options:

  • Surgery – the typical treatment for perianal basal cell carcinoma is a surgical procedure to remove the cancerous area. Your surgeon will work to preserve as much surrounding healthy tissue as possible. 
  • Chemotherapy – you may need to undergo chemotherapy to destroy any cancerous cells that couldn’t be removed surgically. During this treatment, medication is used to destroy cancerous cells. Chemotherapy can be taken via an oral (by mouth) pill or intravenously (through a vein).
  • Radiation therapy – radiation treatment uses high-powered energy beams to destroy cancerous cells. You may need to undergo radiation therapy to destroy any cancerous cells that couldn’t be removed surgically.

When should I seek care?

If you experience any of these symptoms, start by voicing your concerns and symptoms to your primary care provider. From there, your doctor may suggest seeing an oncologist for more specialized treatment.

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