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. Key Message New imaging techniques such as capsule endoscopy and balloon-assisted endoscopy have facilitated the early diagnosis of small bowel malignancies, leading to a better understanding of the biology of these tumors and to improved clinical outcomes for the patient. Practical Implications Although relatively rare, the incidence of tumors and polyps in the small intestine has increased over the past 20 years. The use of endoscopic or radiologic techniques is crucial for the detection and resection of polyps. It is highly recommended to perform a submucosal injection of epinephrine-saline solution prior to endoscopic resection. Due to their non-specific symptoms, neuroendocrine tumors are often diagnosed in advanced stages; surgical excision of the primary tumor is key to a better prognosis. The main therapies for neuroendocrine tumors are surgery, chemoembolization, chemotherapy and the use of somatostatin analogues. Small bowel adenocarcinomas are extremely rare but can be highly fatal. Surgical resection is still the core treatment, though fluoropyrimidine and oxaliplatin-based chemotherapy have shown beneficial effects for the treatment of metastatic disease. Amongst the gastrointestinal stromal tumors, 30% are located in the small intestine. The management of gastrointestinal stromal tumors requires a combination of surgery, pathology techniques and pharmacological interventions, including the use of tyrosine kinase inhibitors.