Oncocytic non‐functioning endocrine tumor of the pancreas

Abstract

Herein is presented the case of a malignant non-functioning endocrine tumor of the pancreas with oncocytic features, and a discussion on the high incidence of malignancy in oncocytic endocrine pancreatic tumors. The patient was a 65-year-old woman who showed no paraneoplastic symptoms produced by functioning pancreatic endocrine tumors. The primary tumor was located in the body and tail of the pancreas, and had metastasized to the liver. Tumor cells were arranged in a ribbon-like or trabecular pattern and had an abundant eosinophilic cytoplasm containing numerous mitochondria and neurosecretory granules. The cytoplasm of the tumor cells was intensely stained with an antimitochondrial antigen antibody. Most tumor cells stained positively with Grimelius stain and for chromogranin A. Some tumor cells also stained for synaptophysin. However, the tumor cells negatively stained for hormones such as insulin, glucagon, somatostatin, gastrin, vasoactive intestinal peptide and pancreatic polypeptide, for serotonin, and for pancreatic enzymes such as amylase and trypsin. Analysis of 18 oncocytic pancreatic endocrine tumors, consisting of those reported previously and that in the present case, suggests that the high incidence of malignancy in oncocytic endocrine tumors is associated with the high incidence of non-functioning endocrine tumors among them, most of which are malignant.

Intraductal oncocytic papillary neoplasms of the pancreas and bile ducts: a description of five new cases and review based on a systematic survey of the literature

“…Oncocytic differentiation in pancreatic neoplasms is very rare. Oncocytic variants of pancreatic intraepithelial neoplasia (PanIN), solid pseudopapillary neoplasm, acinar cell carcinoma, pancreatoblastoma, neuroendocrine neoplasm, serous cystic neoplasm, pyloric‐type intraductal tubular adenoma, and intraductal tubular carcinoma have been described [2, 17, 51, ]. Interestingly, oncocytic variants of the tumors presented above are not currently separated as distinct clinicopathologic entities.…”

Canine mammary minute oncocytomas with neuroendocrine differentiation associated with multifocal acinar cell oncocytic metaplasia

“…Although the incidence rate is rather low, human cases of oncocytic neuroendocrine tumors occur in several organs, such as the adrenal medulla, exocrine pancreas, and lungs. 17,27,31 In an extensive previous study, which analyzed a number of human oncocytic breast carcinomas, 24 there were a few cases showing neuroendocrine differentiation accompanied by chromogranin A expression. In the present study, a subpopulation of neoplastic cells consisting of minute tumors revealed finely granular immunoreactivity for chromogranin A, despite the lack of immunoreactivity for synaptophysin and NSE.…”

Recent Updates on Neuroendocrine Tumors From the Gastrointestinal and Pancreatobiliary Tracts

“…Some studies reported that oncocytic tumors have a malignant clinical behavior. 86,87 In the setting of liver metastasis of oncocytic pancreatic NETs, immunohistochemical staining with neuroendocrine markers can help to differentiate hepatocellular carcinomas. Pleomorphic NETs contain more than 20% of tumor cells with marked nuclear pleomorphism (Figure 3, C).…”