Appendix cancer is very rare. The incidence of underlying malignancy in appendicitis ranges between a meagre 0.5% and 1.7%. Small wonder then that appendix cancer is very often misdiagnosed as appendicitis, since the early symptoms of both overlap and appendix cancer often doesn’t manifest in symptoms until the later stages.

Besides the rarity of appendix cancer, the limitations in standard imaging techniques also lead to frequent misdiagnosis. If a patient is 40-plus with an appendiceal diameter of over 10 mm, he/she is at a greater than 3-fold increased risk of malignancy if presenting with appendicitis.

Appendix cancer develops when healthy cells in the appendix mutate and grow out of control, forming a tumour. Doctors more often than not detect such tumours during surgery for appendicitis or during an imaging test for an unrelated condition.

Common Symptoms Of Appendix Cancer

Weight loss
Bloating
Early satiety
Fatigue
Nausea
Abdominal pain
Change in bowel habits

Doctors concur that appendix cancer is often mistaken for appendicitis, which is primarily due to the very low incidence of this cancer. So, appendix cancer is rarely considered when patients present with these symptoms. Appendiceal cancer tends to be diagnosed at a later stage compared to many other cancers.

So, if you are diagnosed with appendicitis and your symptoms persist even after a few weeks, it’s wise to seek a second opinion. Appendix cancer patients will typically have abdominal pain and fever. However, since appendix cancer symptoms are quite similar to a clutch of other conditions, a patient will usually have to wait till surgery to confirm the cancer diagnosis.

How Is Appendix Cancer Diagnosed?

Diagnosis is usually reached after appendectomy. Sometimes, existing tumours show up on imaging tests or surgery for an unrelated condition. Tests prescribed include:

Imaging tests: A CT scan or an MRI can reveal signs of cancer spread. When it spreads, appendix cancer advances to nearby abdominal organs or the tissue lining them (peritoneum).
Laparoscopy: A long, slender fibre-optic instrument is inserted into the abdomen through an incision. A small camera fitted to the instrument captures images of the appendix and projects those onto a screen.
Biopsy: In this test, tissue sample is harvested and sent to a path lab to check for cancer cells. Since biopsy of the appendix is tricky, tissue is often taken from an adjacent region where the cancer has spread.
Blood tests: In case biopsy comes positive for appendix cancer, you will need lab tests to check protein levels to help determine how advanced the cancer is.

Summing Up Reasons For Misdiagnosis

Overlapping symptoms: Both appendicitis and appendix cancer present with symptoms like abdominal pain, nausea and changes in bowel habits.
No early symptoms: Appendix cancer often progresses without perceivable symptoms till it reaches an advanced stage.
Low incidence: Since appendix cancer is so rare, doctors may not suspect it initially, focusing more on appendicitis.
Limitations of imaging: Standard imaging techniques like CT scan may not reliably project the appendix or detect early signs of cancer.
Delayed diagnosis: Overlapping symptoms and diagnostic limitations mean appendix cancer is often discovered only during surgery for suspected appendicitis or during imaging for unrelated conditions.