Carcinoid tumors are a type of neuroendocrine tumor that can develop in the appendix, gastrointestinal tract, or lungs. These tumors are occasionally found growing in the appendix after it is removed during an episode of appendicitis.
The majority of carcinoid tumors in children are small, slow-growing, and benign. In rare cases, these tumors can grow more quickly and spread to other sites in the body.
About 10 percent of children with multiple endocrine neoplasia type 1 (MEN1) develop carcinoid tumors.