High Incidence of Appendix Carcinoid Tumors Among Candidates for Bariatric Surgery: Diagnostic and Therapeutic Implications

Abstract

Although the appendix has been recognized as a preferential site for carcinoid tumors in obese patients, no definitive guidelines are so far available regarding the management of these patients when candidates for bariatric surgery. This study was designed to fill that gap. Between 2000-2008, 558 patients underwent bariatric procedures. Appendectomy was routinely performed in 477 cases. Their charts were retrospectively retrieved and histopathology responses on surgical specimens were recorded. We aimed to assess: incidence of appendix carcinoid tumors (ACTs) and any possible risk-factor; modality of diagnosis (pre-, intra- or post-operatively); impact on the planned bariatric procedure; treatment reserved to such cases. Typical ACTs were diagnosed in 7 patients (1.4%) (median age: 33 years; median BMI: 49 kg/m²; males/females: 1/6). Four were diagnosed intra-operatively. Because of dimensions (<2 cm) and absence of mesoappendiceal or serosal involvement, simple appendectomy was performed during bariatric procedure, as planned. Three were diagnosed post-operatively (all <2 cm). In 1 case right hemicolectomy was performed 1 month later due to mesoappendiceal involvement. No appendectomy-related complication was encountered. All patients remained tumor-free during follow-up (mean: 64 months; range, 25-92). Young age, female sex, high BMI and diabetes mellitus resulted significantly associated with ACT. Our study sustains routine appendectomy or at least careful investigation of the appendix during bariatric surgery. For tumors <2 cm without mesoappendiceal or serosal involvement, simple appendectomy proved sufficient. Bariatric surgery did not have a negative effect on the treatment of malignancies that are discovered intra- or post-operatively.

ENETS Consensus Guidelines for Neuroendocrine Neoplasms of the Appendix (Excluding Goblet Cell Carcinomas)

“…The reported incidence has increased in more recent years [1,6]; however, the overall incidence rate is probably roughly within the same range between different races, although some differences have been reported [1,12,15,16,17,18]. Furthermore, common practice in performing appendicectomies may also influence the reported incidence of appendiceal NEN [19,20]. …”

Risk factors associated with gastroenteropancreatic neuroendocrine tumors in a cohort of 2.3 million Israeli adolescents

“…A few case reports have described an incidental finding of NET, most frequently gastric NET, among morbidly obese patients before or after bariatric surgery . One small study showed a high incidence of appendiceal NET among candidates for bariatric surgeries …”

Familial appendiceal tumours in Diffuse Peritoneal Adenomucinosis and peritoneal mucinous carcinomatosis: A rare familial predisposition?

“…There are reports of patients with inflammatory bowel disease having a higher incidence of appendix cystadenomas, [12] and bariatric patients having a higher incidence of appendix carcinoid tumours. [13] It is felt that screening is not warranted considering the low incidence of these types of tumours.…”