Pancreas endocrine neoplasia

Synaptophysin, also called protein p38, is a glycoprotein initially found in small vesicle membranes of neurons and of chromaffin cells in the adrenal medulla. It has been routinely used as a broad-spectrum marker in normal and neoplastic neuroendocrine cells including those of the pancreas however, strong synaptophysin immunoreactivity has been well-documented in tumors without any endocrine differentiation including solid-pseudopapillary neoplasm (SPN) of the pancreas, which is one of the most important differential diagnoses of endocrine neoplasia in this organ. 

Pancreatic endocrine neoplasms (PENs) are the majority of the endocrine neoplasms in the pancreas.Most PENs are sporadic. However, these tumors also constitute one of the major components of the multiple endocrine neoplasia I (MENl) syndrome or may arise in patients with vHL syndrome. Those that are associated with increased serum levels of hormones and lead to corresponding symptoms are referred to as functional and are named according to which hormone they secrete (e.g., insulinoma—42% of all functional variants, gastrinoma—24%, glucagonoma—14%,... 

Mulliplc endocrine neoplasias are inherited disorders. The syndromes are usually transmitted in an autosomal dominant pattern. The endocrine glands most often affected are the parathyroid, pituitary, pancreas, thyroid and adrenal. It is postulated that the cell types involved in these tumours have a common embryological precursor. There arc three well-dcrmed multiple endocrine neoplasia syndromes (Fig. 2). 

In the pediatric population, pancreatic tumors are very unusual entities. They account for less than 5% of all malignancies in children. These tumors may arise from the exocrine or endocrine pancreas. Exocrine neoplasias include ductal adenocarcinoma, acinar adenocarcinoma, pancreaticoblastoma, or infantile adenocarcinoma. Endocrine tumors or islet cell tumors are named after the hormone produced, with insulinoma being the most common in children (Walker 1996). 

Recurrent anastomotic ulcers when they occur are usually found on the jejunal side of the anastomosis (Fig. 5.8a). In patients who present with persistent or complex duodenal or anastomotic ulcer, especially if associated with diarrhoea, weight loss, and liver metastasis, Zollinger-Ellison syndrome should be suspected. The syndrome consists of recurrent intractable peptic ulcers caused by hypergastrinae-mia produced by gastrin-secreting tumours of the pancreas (75%) or duodenum (15%) (Hirschowitz 1997). Tumour localisation is critical to aid in the identification of patients with potentially respectable disease (Berg and Wolfe 1991). Twenty percent of patients have multiple endocrine neoplasia type I which includes parathyroid, pituitary, and adrenal tumours. 

Neoplasias that arise from the endocrine portion of the pancreas can be classified as secretory or non-secretory (Gouya et al. 2003). When secretory, the endocrine tumor will be subclassified according to the type of hormone produced (insulin hormone, gastrin hormone, or active peptides). Insulinomas are the most common endocrine tumors, while glucagonomas or somatostatinomas have not been reported in children. 

The initial hazard identification of pancreatic toxicity in a prechnical study is always concerning because of the potentially serious human health risks, which may include fulminant, hfe-threatening cases of DIAP or a lifelong iUness, such as CP, type 1 diabetes, or pancreatic neoplasia. Because both the exocrine and the endocrine pancreas have enormous reserve capacities and there are limited sensitive and specific biomarkers to detect pancreatic injury in both animals and humans, there is always the concern that subclinical DIAP may initially go undetected in humans. Further, AP may progress until a threshold of severity is evident in minimally or asymptomatic healthy human volunteers exposed to drug candidates with unknown risks and/or in previously healthy patients that receive standard-of-care agents with marked... 

---