Small Bowel Neoplasias: Current Options for Diagnosis, Staging and Therapeutic Management

Although small bowel polyps and tumors are rare, their incidence has increased significantly over the past 30 years. Small bowel malignancies can be classified depending upon their cellular origin into four principal histologic types: adenocarcinomas, lymphomas, neuroendocrine tumors or carcinoids and lymphomas, which also include gastrointestinal stromal tumors. The relative ‘rarity’ of these tumors has led to stagnation in the development of effective curative or adjuvant therapies. Thus, the prognosis of most of these tumors is still dismal. Nevertheless, hope is now on the horizon as new methods such as capsule endoscopy and balloon-assisted enteroscopy have contributed to a rise in the diagnosis of these lesions and a diagnosis at earlier stages. Using balloon-assisted enteroscopy methods it is possible to resect most small bowel polyps such as adenomas and hamartomas. Improved imaging methods have led to a better understanding of these pathologies and hopefully will bring new hopes in therapy. In addition, multi-center studies are being performed to determine the best therapeutic options for small bowel tumors. © 2013 S. Karger AG, Basel D ow nl oa de d by : 54 .7 0. 40 .1 1 10 /2 /2 01 7 4: 55 :2 7 P M 11 Gastrointest Tumors 2014;1:9–17 DOI: 10.1159/000355210 Fry et al.: Small Bowel Neoplasias: Current Options for Diagnosis, Staging and Therapeutic Management www.karger.com/gat © 2013 S. Karger AG, Basel have an increased risk of malignancies, up to a 100% risk of colorectal cancer in patients with FAP [11] . The risk of extracolonic (i.e. small bowel) malignancies varies according to the syndrome. Classically it has been thought that only adenomatous polyps present a risk of malignant transformation, but newer data also show that hamartomatous polyps have foci of adenoma, and these have also been associated with an increased risk of cancer development [11] . Patients with Cronkhite-Canada syndrome are also at increased risk of developing small bowel cancer [6] . Patients with FAP are at increased risk of developing duodenal, ampullary and jejunal adenocarcinomas [11] . The overall risk of small bowel cancer in FAP is 4–12%, or up to 300-fold higher than in the general population [2, 7–9] . Saurin et al. [13] have described that patients with mutations in the central part of the APC gene have more severe duodenal polyposis. Genotypic-phenotypic characterizations to correlate with duodenal polyposis and jejunal severity may also aid in determining screening methods (esophagogastroduodenoscopy and duodenoscopy versus double balloon enteroscopy or capsule endoscopy) and surveillance intervals of these patients [14] . In addition, we believe that searching for polyps beyond the duodenum in FAP is important because of the reported occurrence of jejunal adenocarcinoma in these patients [11] . Surveillance in Polyposis Syndromes Surveillance of patients with adenomatous and hamartomatous polyposis syndromes is important to detect and resect polyps in the gastrointestinal tract in order to decrease the incidence of cancer, but also to avoid complications such as bleeding, obstruction and intussusception [11] . Surveillance methods include capsule endoscopy, balloon-assisted enterMalignant tumors Primary tumors Metastatic tumors NET Lung adenocarcinoma Adenocarcinoma Squamous cell carcinoma GIST Small cell carcinoma B cell lymphoma Large cell carcinoma Follicular lymphoma Breast carcinoma Mantel cell lymphoma Lobular Diffuse large B cell lymphoma Ductal Burkitt-like lymphoma Melanoma Burkitt lymphoma Amelanotic melanoma T cell lymphoma Ovarian adenocarcinoma Enteropathy-type T cell lymphoma Carcinosarcoma Anaplastic lymphoma Gastric adenocarcinoma Peripheral T cell lymphoma Colon adenocarcinoma Natural killer cell lymphoma Gallbladder adenocarcinoma Sarcoma Renal cell carcinoma Leiomyosarcoma Pelvic adenocarcinoma Histiocytic sarcoma Pancreatic carcinoma Ewing’s sarcoma Osteosarcoma Choriocarcinoma Testicular germ cell tumor Benign polyps and tumors Adenoma Hemangioendothelioma Lipoma Lymphangioma Leiomyoma Lymphatic cyst Hamartoma Aberrant pancreas Hemangioma Myxoma Table 1. Small bowel polyps and tumors D ow nl oa de d by : 54 .7 0. 40 .1 1 10 /2 /2 01 7 4: 55 :2 7 P M 12 Gastrointest Tumors 2014;1:9–17 DOI: 10.1159/000355210 Fry et al.: Small Bowel Neoplasias: Current Options for Diagnosis, Staging and Therapeutic Management www.karger.com/gat © 2013 S. Karger AG, Basel oscopy, push enteroscopy, intraoperative endoscopy, or radiologic techniques such as enteroclysis, computed tomography (CT) enteroclysis or magnetic resonance enteroclysis. Capsule endoscopy has proved to be useful for the evaluation of the small bowel in patients with polyposis syndromes, also when compared to other imaging methods such as magnetic resonance imaging, CT enterography and push enteroscopy [11] . Therapy of Small Bowel Polyps The issue of resective or ablative therapies in patients with familial polyposis syndromes is gaining increasing importance. Most polyps in patients with Peutz-Jeghers syndrome and FAP can be removed endoscopically [11, 12] . We want to emphasize that careful attention must be paid to the endoscopic removal technique as there are some reported and many unreported cases of perforation. Removal of polyps is performed using either snare polypectomy or mucosectomy techniques. When dealing with larger polyps with thick stalks and flat lesions, we always proceed to endoscopic resection by submucosal injection of epinephrine-saline solution (1: 20,000 to 1: 100,000) (‘submucosal cushion’). The submucosal cushion is an essential technique when performing advanced polypectomy within the luminal gastrointestinal tract because the small bowel has a very thin wall and the submucosal cushion is especially suited for resection of these mucosal lesions. The submucosal cushion basically entails the elevation of the target lesion as a result of submucosal injection of various liquid substances [12] . By raising the polyp from the submucosa, the endoscopic resection is facilitated and a more complete resection of the neoplastic tissue can be achieved. In addition, by lifting the submucosa from the deeper layers of the gut wall, the depth of injury to the gut wall a b c Fig. 1. Small bowel polyps. a Hamartoma in Peutz-Jeghers syndrome. b Adenoma in FAP syndrome. c Jejunal lipoma.