Neuroendocrine Tumor of the Appendix in Children.

Neuroendocrine tumor (NET) of the appendix is the most common gastrointestinal epithelial tumor in children. The utility of serum markers or the indication for hemicolectomy has not been established in children. In 45 children diagnosed with appendiceal NET, 89% NETs were incidentally found following appendectomy performed for suspected acute appendicitis. The median age was 12 years, and 56% patients were female. Postoperative somatostatin scan (n=5), serum chromogranin A (n=4), and urine 5-HIAA (n=9) were all within normal limits. Pathology slides of 35 patients showed mesoappendiceal invasion in 29% patients, and vascular invasion in 6% patients. Seven patients (16%) underwent hemicolectomy for invasion of mesoappendix (n=5), tumor near the resection margin (n=1), and tumor size 1.5 cm with vascular invasion (n=1). Only 2 hemicolectomy specimens showed disease: one in the appendiceal stump and the other as a micrometastasis in a mesenteric lymph node. There were no recurrences and all patients were alive and without evidence of disease at last follow-up. Pediatric appendiceal NET tends to have a benign clinical course with excellent prognosis. In the absence of carcinoid syndrome, postoperative scans and serum biomarkers do not seem to be useful. With completely resected tumors, the indication for hemicolectomy is unclear.