Adenocarcinoid tumor is a subtype of appendiceal cancer, or cancer of the appendix. The appendix is a small hollow tube attached to the first section of the large intestine (cecum) and may be part of the lymphatic system; however, the function of the appendix is unknown. There are two types of adenocarcinoid tumors of the appendix: 1) goblet cell and 2) tubular type. Cancer of the appendix is extremely rare.

Symptoms of adenocarcinoid tumor are similar to appendicitis and may include abdominal bloating and discomfort; decreased appetite; nausea and vomiting; pain in the right lower abdomen or pelvis; a pelvic mass; fluid in the abdomen (ascites); protrusion of the navel; changes in bowel function; and intestinal blockage.

Treatment for adenocarcinoid tumors of the appendix depend on the stage and subtype. Most adenocarcinoid tumors of the appendix can be treated with surgical removal of the appendix (appendectomy). For adenocarcinoid tumors that have spread beyond the appendix, further treatments, such as partial removal of the large colon (hemicolectomy); lymph node removal; removal of the peritoneum; intravenous chemotherapy; or heated (hyperthermic) chemotherapy to the abdomen (HIPEC), may be required.