A Case of a Neuroendocrine Tumor of the Appendix Presented with Appendicitis in a 10-year-old Girl

Abstract

A 10-year-old girl presented to the emergency department with pain in the right lower quadrant of abdomen. An abdominal contrast-enhanced CT scan revealed findings consistent with acute appendicitis, showing a swollen appendix with a high attenuation area, having coproma-like appearance, and high absorbance of peripheral fat. She underwent laparoscopic appendectomy. The histopathological examination showed a 1.1 × 1.5 cm mass at the middle portion and the lumen was almost obstructed. Histopathological examination detected relatively evenly sized tumorous cells with near-circular-shaped nucleus and sickly eosinophilic cytoplasm spreading from the submucosal layer to the subserosal layer in the middle of the appendix and forming a funicular sequence. Abnormal mitosis was also seen and the Ki67 labeling index was 8.4%. We diagnosed the case as NET G2 of the appendix. Lymph vessel investigation was slightly positive, but no vascular investigation was detected. We selected close observation and the patient showed good progress, with no recurrence for 6 months postoperatively. Prognosis of NET in children is good, but it is a rare entity and no clear therapeutic guidelines have been established. Further accumulation of clinical cases is expected.