Neuroendocrine neoplasms of the small intestine and appendix-management guidelines (recommended by the Polish Network of Neuroendocrine Tumours)

This study presents the revised Polish guidelines regarding the management of patients suffering from neuroendocrine neoplasms (NENs) of the small intestine and appendix. The small intestine, especially the ileum, is the most common location for these neoplasms. Most are well differentiated and slow growing. Their symptoms may be atypical, which can result in delayed or accidental diagnosis. Appendicitis is usually the first manifestation of NEN in this location. Typical symptoms of carcinoid syndrome occur in approximately 20-30% of patients suffering from small intestinal NENs with distant metastases. The main cause of death in patients with carcinoid syndrome is carcinoid heart disease. The most useful laboratory test is the determination of chromogranin A, while concentration of 5-hydroxyindoleacetic acid is helpful in the diagnostics of carcinoid syndrome. For visualisation, ultrasound, computed tomography, magnetic resonance imaging, colonoscopy, video capsule endoscopy, double-balloon enteroscopy, and somatostatin receptor scintigraphy may be used. A detailed histological report is crucial for the proper diagnostics and therapy of NENs of the small intestine and appendix. The treatment of choice is surgical management, either radical or palliative. The pharmacological treatment of the hormonally active and non-active small intestinal NENs as well as NENs of the appendix is based on long-acting somatostatin analogues. In patients with generalised NENs of the small intestine in progress during the SSA treatment, with good expression of somatostatin receptors, the first-line treatment should be radioisotope therapy, while targeted therapies, such as everolimus, should be considered afterwards. When the above therapies are exhausted, in certain cases chemotherapy may be considered.