Types of Appendix Cancer Tumors

Understanding appendix cancer 

The appendix is a pouch-like tube that is attached to the cecum (the first section of the large intestine or colon) and is part of the gastrointestinal (GI) tract. The appendix is generally thought to have no significant function in the body but may play a role in the lymphatic, exocrine, or endocrine systems.

Appendix cancer, also called appendiceal cancer, occurs when healthy cells in the appendix change and grow out of control and form a tumor. These tumors can be cancerous or benign, and may spread (metastasize) to other parts of the body.

Appendix cancer tumor types

The two main types of appendix cancer are called carcinoid tumors and carcinomas. 

Carcinoid tumors are the most common appendix cancers, making up about half of those diagnosed. They are usually found at the tip of the appendix. Because there are no symptoms, these tumors are often detected after the appendix has been removed. A carcinoid tumor that has not spread has a high chance of successful treatment with surgery.

Carcinomas of the appendix include:

• Mucinous adenocarcinoma. This common type of appendix cancer is caused by a range of benign to malignant conditions that may occur in the appendix to form a mucocele (swellings or sacs from swelling of the appendix wall, typically filled with mucous). These tumors begin in the appendix but are most often discovered after they have spread to the lining of the abdominal cavity (peritoneum). If the cancer is contained to the appendix, it can be completely removed with surgery. 
• Adenocarcinoid tumors, also called goblet cell carcinoids are less common tumors. They are aggressive tumors and are treated similarly to mucinous adenocarcinoma. 
• Intestinal-type adenocarcinoma accounts for 10% of appendix cancer. This type of cancer is usually found near the bottom or base of the appendix. When these tumors cause symptoms, they are often like symptoms of colorectal cancer.
• Signet-ring cell adenocarcinoma are a rare and aggressive type of appendix cancer. It often occurs in the stomach or colon, and it may cause appendicitis, an inflammation of the appendix that can cause abdominal pain or swelling, loss of appetite, nausea, vomiting, constipation or diarrhea, inability to pass gas, or a low fever that begins after other symptoms.
• Paraganglioma is a rare tumor that develops from cells of the paraganglia, a collection of cells that come from nerve tissue that persist in small deposits after fetal (pre-birth) development. Paraganglia is often found near the adrenal glands and some blood vessels and nerves including in the head and neck region of the body. This type of tumor is usually considered benign and is often successfully treated with the complete surgical removal of the tumor.