A Case of a Neuroendocrine Tumor of the Appendix in a Child

Abstract

According to the Clinical Practice Guidelines for Gastroenteropancreatic Neuroendocrine Neoplasms 2019, ileocecal excision is recommended for tumors with more than 2 cm in diameter or with risk factors such as vascular invasion. However, few studies have been reported on pediatric patients and no clear notion has been established.

We present a case of a neuroendocrine tumor (NET) of the appendix in a child presented with appendicitis. A 12-year-old girl presented to the emergency department with the chief complaint of pain in the right lower quadrant of abdomen. An abdominal contrast-enhanced CT scan revealed findings consistent with early acute appendicitis. She underwent laparoscopic appendectomy with a diagnosis of acute appendicitis. No tumorous lesion was detected macroscopically in the surgical specimen. The histopathological examination, however, showed tumorous cells spreading from the proper mucosal layer to the proper muscular layer at the base of the appendix, and the resection margin was positive for neoplasm. Immunohistochemical staining was positive for synaptophysin and chromogranin A, and the Ki67 index was less than 0.5% ; no mitotic figures were observed. We diagnosed the case as NET G1 of the appendix. Because of the positive surgical margin, we performed additional laparoscopic ileocecal resection with D3 lymphadenectomy 54 days after the appendectomy. Pathologically, tumorous cell metastasis was found in one of the dissected pericecal lymph nodes. The patient was followed up for 20 months with no recurrence.