ABSTRACT
The islet cells of the pancreas, like all other neuroendocrine cells, are designed to produce peptide hormones for systemic release (1,2). Islet cell tumors may be benign or malignant, similar in this manner to tumors derived from other amine precursor uptake decarboxylase cells, such as the thyroid C cells and adrenal medullary cells. Islet cell tumors produce and release hormones in an unregulated manner, causing unique hormone syndromes. Insulinoma is the most common islet cell tumor, followed by gastrinomas, but all islet cell tumors are rare. Functional islet cell tumors of other types occur much less commonly, and individual series are few and limited. Most islet cell tumors produce one or more peptide hormones, although nonfunctional islet cell tumors have been described. This aids diagnosis and provides tumor markers for follow-up surveillance.
