What are the other Names for this Condition? (Also known as/Synonyms)

• Adenoma of Appendix
• Appendicular Adenoma

What is Appendiceal Adenoma? (Definition/Background Information)

• Appendiceal Adenomas are benign epithelial tumors arising in the appendix. The appendix is a small blind pouch of the colon, located at the beginning of the colon (large intestine)
• Appendiceal Adenomas are considered “pre-malignant” tumors. This means that these tumors may turn malignant with time. If these tumors remain untreated, they can develop into cancer of the appendix
• Adenoma of Appendix can be classified as high-grade or low-grade. A high-grade adenoma has a greater risk for malignancy, than a low-grade adenoma (which form the majority of tumors)
• Similar to adenomas (or adenomatous polyps) of the colon, Appendiceal Adenomas may be tubular, villous, or tubulovillous. However, the frequently occurring type noted in the appendix is the sessile serrated polyp/adenoma. Hyperplastic polyps are also occasionally seen in the appendix
• The cause of formation of Appendiceal Adenomas is reportedly due to genetic factors. Most adenomas are observed to form sporadically and are generally difficult to diagnose. Some adenomas within the gastrointestinal tract are associated with a variety of genetic syndromes, such as familial adenomatous polyposis or Gardner syndrome
• In most cases, small-sized tumors do not cause any pain and other significant symptoms. However, larger tumors may present symptoms similar to acute appendicitis, such as severe abdominal pain, nausea and vomiting, and constipation, in some cases
• The mainstay of treatment for Adenoma of Appendix is surgical excision of the tumor. Adenomas can be surgically removed and the measure is usually curative
• If Appendiceal Adenomas are detected early enough, they can be removed and the risk of developing into a malignancy is low. In such cases, the prognosis is good

Who gets Appendiceal Adenoma? (Age and Sex Distribution)

• Appendiceal Adenoma (sporadic tumors) are mostly observed in middle-aged or older adults
• Both males and females may develop these tumors
• In the background of certain genetic disorders, the adenomas may arise in younger individuals
• No racial, ethnic, or geographical predominance is generally noted

What are the Risk Factors for Appendiceal Adenoma? (Predisposing Factors)

The specific risk factors for Appendiceal Adenoma are generally unknown. However, common risk factors for adenomas in the gastrointestinal tract may include:

• Aging: Elderly individuals have a higher risk for developing these tumors
• Presence of predisposing genetic conditions, such as familial adenomatous polyposis (FAP) or Gardner syndrome
• Some individuals with ulcerative colitis (inflammatory bowel disorder) have shown intestinal adenomas

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Appendiceal Adenoma? (Etiology)

Appendiceal Adenoma is caused by genetic mutations that lead to a condition termed dysplasia.

• Dysplasia is the phenomena of disordered growth of the epithelial lining of the small intestine. Genetic mutations lead to cell growths at abnormally high rates. This causes the cells to grow abnormally, forming the tumors characteristic of an adenoma
• In general, adenomas in the digestive tract are noted to appear sporadically; while some appear in the presence of genetic disorders such as familial adenomatous polyposis (FAP) or Gardner syndrome
• The genetic mutations can be either inherited, or caused by exposure to various environmental factors
  • Inherited genetic mutations include those that result from FAP or Gardner syndrome, which are autosomal dominant conditions
  • Environmental factors that cause genetic mutations may include radiation, harmful chemicals in the air, exposure to pollutants, etc.

FAP or Gardner syndrome involves germline mutations on the APC gene, located on chromosome 5. In such cases, the risk of formation of adenoma is very high.

• Sessile serrated polyps and hyperplastic polyps show abnormalities on the MLH1 and MGMT genes, including BRAF gene mutations in some cases
• In many cases, KRAS gene mutations have been noted
• Adenomas also show loss of heterozygosity (LOH) associated with APC gene (tumor suppressor gene)

What are the Signs and Symptoms of Appendiceal Adenoma?

Some Appendiceal Adenomas present signs and symptoms, while others may be asymptomatic and detected incidentally during imaging studies.

The signs and symptoms of Appendiceal Adenoma may include:

• Presence of a palpable mass, when tumors are large
• Swollen abdomen
• The adenomas may form anywhere in the appendix
• Tumors are normally solitary; however, in the background of a genetic disorder, multiple tumors may be observed
• With large-sized adenomas, symptoms similar to acute appendicitis may be noted, which include:
  • Abdominal pain that first originates around the umbilicus and then gradually moves towards a point on the right lower quadrant of the abdomen, called the McBurney’s point
  • Sometimes, the pain can occur anywhere in the upper or lower abdomen, back, or rectum
  • Nausea and vomiting
  • In some, fever, shivering, and chills may be noted
  • Loss of appetite
  • Constipation or diarrhea
  • Occasionally, painful urination and severe cramps can occur

How is Appendiceal Adenoma Diagnosed?

A diagnosis of Appendiceal Adenoma may involve the following tests and exams:

• Physical exam and evaluation of medical history
• Complete blood count (CBC)
• Basic metabolic panel
• X-ray of abdomen
• Ultrasound or CT scan of abdomen
• Screening colonoscopy: A colonoscopy is a test that allows the physician to look at the inner lining of the colon and rectum. A typical colonoscopy involves using a thin, flexible tube (called a colonoscope), with an attached video camera, to view the colon and rectum

A tissue biopsy of the tumor is performed and sent to a laboratory for a pathological examination.

• A pathologist examines the biopsy under a microscope. If it is indeed a polyp, a distinct appearance is noted by the pathologist. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis
• Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
• Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
• Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, and very rarely, electron microscopic studies to assist in the diagnosis

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Appendiceal Adenoma?

The complications of Appendiceal Adenoma may include:

• The tumors may develop to form adenocarcinomas of the appendix, if undetected or left untreated
• Complications may arise from the underlying genetic disorder, if any present
• Large-sized tumors may compress adjoining tissues and structures resulting in additional complications
• Damage to the muscles, vital nerves, and blood vessels, during surgery
• Post-surgical infection at the wound site is a potential complication

How is Appendiceal Adenoma Treated?

Treatment measures for Appendiceal Adenoma may include:

• They are removed during a colonoscopy and sent for testing, in order to ensure that they are non-malignant or harmless
• A complete surgical resection of the tumor is usually curative. The following procedures may be considered:
  • Open appendectomy: It involves making a deep incision on the lower abdomen and removing the appendix from the surrounding abdominal organs
  • In laparoscopic approach, a surgeon makes 3 or 4 small incisions for insertion of the camera and the laparoscopic instruments and the appendix is cut and removed
  • Hemicolectomy, if necessary, which is the partial removal of the affected portion of the colon, along-with the tumor
• Undertaking treatment of underlying genetic disorder, as necessary

Regular observation and periodic checkups to monitor the condition is strongly recommended following treatment.

How can Appendiceal Adenoma be Prevented?

Currently, there are no known preventative measures against Appendiceal Adenoma. However, if the tumor is associated with a genetic disorder, the following points may be considered:

• Genetic counseling and testing: If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Regular health check-ups might help those individuals with a history of the condition in the immediate family and help diagnose the tumor early

Regular medical screening at periodic intervals with blood tests, scans, and physical examinations, are mandatory. Often several years of active vigilance are crucial and necessary.

What is the Prognosis of Appendiceal Adenoma? (Outcomes/Resolutions)

With prompt diagnosis and removal of the tumor, Appendiceal Adenoma does not develop into cancer and the prognosis is good.

• Low-grade adenomas have a lower risk for development to invasive adenocarcinomas, than high-grade adenomatous tumors
• Large-sized adenomas in individuals with genetic disorder (such as familial adenomatous polyposis) and seen with high-grade dysplasia, have a greater potential for adenocarcinoma development

Additional and Relevant Useful Information for Appendiceal Adenoma:

The following article link will help you understand other cancers and benign tumors:

http://www.dovemed.com/diseases-conditions/cancer/