The appendix is a tube that looks like a small sack or pouch. It’s connected to the colon near the beginning of the large intestine.
The appendix doesn’t have a known purpose. However, it may have something to do with the immune system.
Appendix cancer is sometimes called appendiceal cancer. It occurs when healthy cells become abnormal and grow rapidly. These cancerous cells become a mass or tumor inside the appendix. When the tumor is malignant, it’s considered cancerous.