The Role of Wireless Capsule Endoscopy (WCE) in the Detection of Occult Primary Neuroendocrine Tumors
Manuele Furnari1, Andrea Buda2, Gabriele Delconte3, Davide Citterio3, Theodor Voiosu4, Giovanni Ballardini3,
Flaminia Cavallaro3, Edoardo Savarino5, Vincenzo Mazzaferro3, Emanuele Meroni6
1) Department of Internal Medicine, Gastroenterology Unit, IRCCS, University of Genoa, Italy;
2) Gastroenterology Unit, Santa Maria Del Parato Hospital, Feltre, Italy;
3) Department of Surgery, Endoscopy and Gastrointestinal Surgery Units, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy;
4) Gastroenterology Department, Colentina Clinical Hospital, Bucharest, Romania;
5) Department of Surgery, Oncology and Gastroenterology, Gastroenterology Unit, University of Padua, Italy;
6) Regional Hospital Beata Vergine, EOC, Mendrisio, Switzerland
Background & Aims: Neuroendocrine tumors (NETs) are a heterogeneous group of neoplasms with unclear etiology that may show functioning or non-functioning features. Primary tumor localization often requires integrated imaging. The European Neuroendocrine Tumors Society (ENETS) guidelines proposed wireless-capsule endoscopy (WCE) as a possible diagnostic tool for NETs, if intestinal origin is suspected. However, its impact on therapeutic management is debated. We aimed to evaluate the yield of WCE in detecting intestinal primary tumor in patients showing liver NET metastases when first-line investigations are inconclusive.
Method: Twenty-four patients with histological diagnosis of metastatic NET from liver biopsy and no evidence of primary lesions at first-line investigations were prospectively studied in an ENETS-certified tertiary care center. Wireless-capsule endoscopy was requested before explorative laparotomy and intra-operative ultrasound. The diagnostic yield of WCE was compared to the surgical exploration.
Results: Sixteen subjects underwent surgery; 11/16 had positive WCE identifying 16 bulging lesions. Mini-laparotomy found 13 NETs in 11/16 patients (9 small bowel, 3 pancreas, 1 bile ducts). Agreement between WCE and laparotomy was recorded in 9 patients (Sensitivity=75%; Specificity=37.5%; PPV=55%; NPV=60%). Correspondence assessed per-lesions produced similar results (Sensitivity=70%; Specificity=25%; PPV=44%; NPV=50%). No capsule retentions were recorded.
Conclusions: Wireless-capsule endoscopy is not indicated as second-line investigation for patients with gastro-entero-pancreatic NETs. In the setting of a referral center, it might provide additional information when conventional investigations are inconclusive about the primary site.
Key words: wireless capsule endoscopy – non-functioning endocrine tumor – NET – diagnosis – diagnostic yield.
Abbreviations: DBE: double balloon enteroscopy; GEP-NET: gastro-entero-pancreatic neuroendocrine tumor; GI: gastrointestinal; ENETS: European Neuroendocrine Tumor Society; NET: neuroendocrine tumor; SSRS: somatostatin receptor scintigraphy; WCE: wireless capsule endoscopy.