Pediatric neuroendocrine carcinoid tumors: Management, pathology, and imaging findings in a pediatric referral center

Background: While neuroendocrine (carcinoid) tumors are increasingly recognized in the adult population, they are often not suspected in children.

Procedure: Retrospective review of all well-differentiated neuroendocrine (carcinoid) tumors was performed based on pathology reports from a quaternary pediatric medical center between January 2003 and June 2016. Clinical presentations, treatment approaches, imaging findings, and outcomes were reviewed and analyzed.

Results: A total of 45 cases of pathology-proven carcinoid tumor were reported with an average age of 14.1 years (range: 7-21 years, SD: 2.8 years). Of these cases, 80% (36) were appendiceal, 11% (5) bronchial, 2% (1) colonic, 2% (1) gastric, 2% (1) enteric, and 2% (1) testicular. Metastases were observed in one (3%) appendiceal, one (100%) enteric, and two (40%) bronchial cases. No recurrence was demonstrated in any appendiceal carcinoid cases. Recurrence was seen in one of three extra-appendiceal gastrointestinal tumors. Tumor site and size significantly correlated with metastases and recurrence.

Conclusions: Contrary to recent epidemiological investigations in adults, appendiceal carcinoid tumors remain the most common site for pediatric carcinoid tumors. Appendiceal carcinoid tumors exhibited benign clinical courses without recurrence during short-term follow-up. Extra-appendiceal gastrointestinal carcinoid tumors exhibited much more aggressive behavior with greater metastases and recurrence. Bronchial carcinoid tumors demonstrated good clinical response to resection even in cases with mediastinal lymph node involvement. While increased use of urine 5-HIAA levels and somatostatin receptor-specific imaging might improve detection and guide management of extra-appendiceal carcinoid tumors, longer-term follow-up is needed.