Pancreatic Endocrine Tumors

Abstract

Pancreatic endocrine tumors are relatively uncommon, accounting for approximately five to ten cases per million persons per year (Heitz et al. 2004). They may be classified as functioning or nonfunctioning. Functioning tumors (those with secretory neuropeptide function) are usually associated with classical syndromes. These include VIPomas, gastrinomas, glucagonomas, and insulinomas (Ramage et al. 2005). At least one third of the tumors may be nonfunctioning, despite typical pathological appearances of well-differentiated endocrine tumors or carcinomas (Clarke et al. 1997). Circulating levels of gut hormones may be detected even in the absence of symptoms (Clarke et al. 1997; Rindi et al. 2006).

The primary management of these tumors should be surgical resection wherever possible, as this offers the only chance of cure (Ramage et al. 2005). Given the rarity of these tumors, and the potential complexity of surgery, a multidisciplinary team approach in a small number of regional or supraregional units is likely to result in optimal management (Ramage et al. 2005). Accurate preoperative imaging is essential for the planning of the correct procedure and at a minimum will include CT or MRI (Oberg 2000). If the clinical course permits, radionuclide scintigraphy with Octreoscan imaging and the emerging use of PET CT with ¹⁸FDG PET or ¹⁸F-DOPA may contribute important details (Oberg 2000). Surgery may still be considered if there are regional lymph nodes and liver metastases, which could be resected at the time of the primary surgery; however, each case should be assessed on its own merit. Other techniques, including radio-frequency ablation, may be considered. After operation, the suitability of adjuvant treatment may be discussed in the light of the operative and histopathological findings. Review of the pathology and risk factors is best carried out by a dedicated histopathologist with an interest in pancreatic endocrine tumors (Rindi et al. 2006).