Appendicular Malignancy

Appendiceal cancer is a type of cancer that grows from cells that make up the appendix. The appendix is a small pouch of tissue in the abdomen. It is part of the intestines and colon, which absorb nutrients and remove waste from the body. We do not know what the appendix does, but it may help the immune system. There are two main types of appendiceal cancer: epithelial appendiceal cancer and neuroendocrine appendiceal cancer.

Epithelial appendiceal cancer grows from cells that make up the lining of the appendix. It may also be called adenocarcinoma. These cells help make a jelly-like substance called mucin. Mucin protects the lining of the stomach, intestines, and appendix. Most epithelial appendiceal cancers can lead to a build-up of mucin, which can cause the appendix to rupture. When mucin from the appendix builds up in the abdomen, it causes a condition called pseudomyxoma peritonei, or PMP.

Mucinous neoplasms are a rare and complex type of epithelial appendiceal cancer. Depending on how the cells look under a microscope they may be low grade (LAMN) or high grade (HAMN) and may spread to other parts of the body.

Neuroendocrine tumors of the appendix, grow from cells called enterochromaffin cells (ECs). ECs make chemicals involved in digestion and movement in the intestines. Neuroendocrine tumors of the appendix are the most common type of appendiceal cancer. They are also called carcinoid tumors.

Appendiceal cancer can spread to different parts of the abdomen directly from the appendix, usually when it ruptures. Less often, appendiceal cancer can spread through lymph nodes to areas outside the abdomen.

Benign Lesion of Small-Intestine

Most tumors of the small intestine are noncancerous (benign). These include tumors of fat cells (lipomas), nerve cells (neurofibromas), connective tissue cells (fibromas), and muscle cells (leiomyomas). Most noncancerous tumors of the small intestine do not cause symptoms.