ABSTRACT
The endocrine system is a group of organs responsible for production of hormones and proteins that contribute to and control metabolic body functions. Microscopically, these organs are primarily composed of epithelial cells; however, cytology from the endocrine organs is often distinctly different from cytology of other epithelial organs. Endocrine cells of the pancreas are found in small islets that contain multiple types of cells. Endocrine pancreas would be identified as groups of cell free nuclei on a background of lightly basophilic cytoplasm. Tumors of the endocrine pancreas are most likely to originate from the ß islet cells, the most numerous endocrine cells in pancreatic islets, responsible for the production of insulin causing an insulinoma. Adrenal medullary cells have a classic endocrine appearance as they are derived from ectoderm of the neural crest. Hyperplastic and neoplastic lesions that may lead to enlargement of the adrenal glands and sampling for cytology may occur in the adrenal cortex or adrenal medulla.
