What is anal adenocarcinoma?Adenocarcinoma of the anus, or adenocarcinoma of the anus, is rare cancer and accounts for approximately 5-10% of all anal cancers. Anal adenocarcinoma also has two types: colorectal adenocarcinoma, which arises from the glandular cells of the mucous membrane lining the colon adjacent to the rectum. Another type is extra mucosal adenocarcinoma that originates from the glands of the anal canal.
What is the anus?The anus is the outer lower end of the intestine. Once digested, food travels from the stomach to the small intestine. It then travels from the small intestine to the main part of the large intestine called the colon. The large intestine absorbs water and salt from digested food and sends it back to the bloodstream. The rest is waste known as feces or stool. Stool accumulates in the last part of the intestine and then is excreted out of the body through the anus.
Disease CausesThere is no well-known cause, but risk factors such as having anal warts, human papillomavirus infection, HIV infection, older age, male gender, cigarette smoking, poor dietary intake with low fiber, and having multiple sexual partners are considered risk factors for developing anal adenocarcinoma.
Signs and symptomsIn most cases, the patient is asymptomatic and is only diagnosed at an advanced stage of cancer. Some initial warning signs and symptoms:
- Change in bowel habits, constipation, diarrhea, or more frequent urge to pass stool.
- Dark color stool due to the presence of blood in the stool
- Feeling as if the bowels are not empty after defecation.
- Bleeding from the anus
- Pain in the abdomen
- Un explained weight loss
DiagnosisThe following diagnostic tests and procedures can be used to make a diagnosis. These are
- Endoscopic examination of the anus, rectum, and large intestine. Endoscopy is a procedure that allows the doctor to visualize the internal organs of the body directly through the endoscope.
- Computed tomography (CT-pelvis) helps to differentiate squamous cell cancer of the rectum from anal cancer.
- Biopsy of the lesion/tumor and histopathological examination