Anal Cancer Clinical Presentation

Updated: Sep 15, 2022
  • Author: Thomas R Dekoj, MD; Chief Editor: N Joseph Espat, MD, MS, FACS  more...
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Patients with anal cancer or its precursor lesion, anal intraepithelial neoplasia (AIN), may be asymptomatic or may present with a wide range of complaints, including the following [24] :

  • Anal or pelvic pain and anal bleeding (approximately half of patients)
  • Sensation of rectal mass (approximately 30%)
  • Local wetness and irritation
  • Prolapse of tissue
  • Incontinence of flatus or liquid or solid stool
  • Obstipation

Approximately 19% of patients wait 6 months or more to seek medical care after symptom onset. Once patients do present, delayed diagnosis or misdiagnosis is unfortunately frequent; in one review, 27% of anal cancers were diagnosed as hemorrhoids on the patient's first visit to a primary care provider. [25]

Denial or reluctance on the part of many patients to seek medical attention for such complaints, as well as the similarity of those signs and symptoms to the manifestations of benign anorectal disease, help explain why anal cancer has historically had a very long lag time (up to 2 years on average) between initial symptoms and diagnosis. [26] More recent data suggest that the average time to diagnosis from onset of symptoms is 7.4 months and 3.2 months after the first visit to a physician. [25]  A patient complaint such as "hemorrhoids", anal mass, or bleeding should always warrant a physical examination, with immediate referral to a colon and rectal surgeon for abnormal appearance, refractory disease, or presence of a mass.  

Although the link between human papillomavirus (HPV) and AIN/anal cancer is well established, a lack of history of anoreceptive sexual practice does not rule out the possibility of HPV infection in the anal area, as there may be a significant "drip-down effect." In addition, non–HPV-related anal squamous cell carcinoma may also occur; such cases are usually attributed to chronic inflammation. [27] However, a history of anoreceptive sexual practice does increase the likelihood of HPV infection and its persistence in the anal area, [28]  and also of AIN and anal cancer.


Physical Examination

Physical examination findings in anal cancer are varied, as the process begins as a microscopic disease that then progresses. In contrast, colon cancer, which most often begins as an area of dysplasia in a polyp, usually is not a microscopic disease at onset.

Anal warts may or may not be present in a patient with anal cancer, as the HPV serotypes responsible for cancer often exist together with, but are distinct from, those that typically cause anogenital warts. [29] Perianal skin irritation from mucus, wetness, and fungal overgrowth may be evident. AIN-affected tissue may have visible mucosal texture changes, vascular pattern abnormalities, and color changes or may be visually indistinct from surrounding skin or mucosa.

A mass may be present in the anal canal, anal verge, or in the perianal skin (see the image below). It is important to make a distinction between these locations, as the specific anatomic location may help determine the treatment scheme of choice.

Anal cancer with typical mass. Courtesy of Luay Ai Anal cancer with typical mass. Courtesy of Luay Ailabouni, MD, FACS, FASCRS.

Usually, an anal cancer mass will have a weeping mucosal covering, with associated moisture changes in the surrounding tissue. The mass typically has a nodular texture and may be fixed to structures in the surrounding areas such as the sphincter complex, pelvic sidewall, vagina, or coccyx area.  

Digital rectal examination to determine the extent of disease as well as fixation to the sphincter or other surrounding structures is a critical examination maneuver. Examination of the inguinal and femoral lymph node basins for lymphadenopathy should be performed.