Differential diagnoses of anal cancer
In early phases, the symptoms resemble common and benign illnesses.
Symptoms related to benign differential diagnoses
- Bleeding from hemorrhoids is the most common differential diagnosis. Many patients are bothered by hemorrhoids, but anal cancer is rare. Therefore, bleeding due to anal cancer is often misinterpreted as hemorrhoids in the beginning and is first discovered during rectal exploration.
- Anal fissure is a relatively common differential diagnosis.
- Unspecific anal itching/discomfort may be mistaken for anal cancer.
Possible differential diagnoses
- Rectal cancer can be mistaken for anal cancer and vice versa when the rectum tumor grows down into the anal canal, or when the anal tumor grows from the dentate line and up into the rectum. Therefore, review of the pathology is essential as the treatment of adenocarcinoma of the rectum and squamous cell carcinoma of the anal canal is different.
- Cervical cancer can be a possible differential diagnosis for large anterior tumors which grow both in the cervix/vagina and anus.
- Benign polyps can be mistaken for an early polypoid tumor.
- Perianal eczema can be mistaken for perianal cancer.
- Large tumors presenting with an abscess can be mistaken for benign perianal abscesses.
- Paget’s disease is easily mistaken for malignant melanoma in situ.