Management and outcome of neuroendocrine tumours of the appendix-a two centre UK experience

Background: Neuroendocrine tumours (NET) of the appendix are rare histopathological neoplasms detected following operation for appendicitis in childhood. The role (if any) for radical surgery notably right hemicolectomy (RHC) has often reflected the 'expert opinion' of adult general surgeons with wider experience of managing NET lesions of the gastrointestinal tract. Critical decisions have focused on (a) tumour size, (b) histology, (c) tumour location/invasion and (d) positive lymph nodes. Against this background we report the clinical outcome of children with 'incidental' appendix carcinoid tumours managed at two regional UK paediatric surgery centres. A critical review of the literature is additionally provided in an effort to define contemporary patterns of care in paediatric surgical practice.

Methods: Hospital records and pathology database(s) identified 27 patients at two UK centres with a confirmed histological diagnosis of appendix NET lesions during January 1997-January 2013. A PUBMED and EMBASE search strategy-(English language publications only), 1975-present, was performed to gather information on all patients younger than 20years at primary diagnosis with NET appendix tumours to review their management and outcomes.

Results: All 27 patients treated at the two institutions had acute appendicitis including 3 cases presenting with an appendix mass. Twenty-five underwent appendicectomy with two having interval operations. Tumours had a maximum diameter of 2-18mm (median 9mm) with 73% of lesions located at the appendix tip. Fourteen (52%) had tumour invading the mesoappendix. All patients underwent appendicectomy only with no single case having RHC or additional surgery. Surveillance studies (5HIAA, chromogranin-A) and imaging including ultrasound or CT were deployed in a minority of patients revealing no abnormality. All 27 cases are alive and well-(mean follow up 5years; range: 9months-16years). The literature highlights varied management strategies and no recorded fatalities with radical surgery in children largely evolving from adult surgical practice.

Conclusions: This study confirms that paediatric patients with 'incidental' NET tumours of the appendix have an excellent prognosis. Consensus guidelines should ideally be developed by paediatric oncology surgeons to avoid unnecessary radical surgery in many otherwise healthy children.