title: 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.
authors.affiliation: Department of Pathology, Meiwa General Hospital, Nishinomiya, Hyogo 663-8186, Japan. sugihara@meiwa-hospital.com
authors.forename: Ayako
authors.initials: A
authors.lastname: Sugihara
authors.forename: Keiji
authors.initials: K
authors.lastname: Nakasho
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Ikuta
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Aihara
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawai
authors.forename: Hiroya
authors.initials: H
authors.lastname: Iida
authors.forename: Hidenori
authors.initials: H
authors.lastname: Yoshie
authors.forename: Chiaki
authors.initials: C
authors.lastname: Yasui
authors.forename: Masao
authors.initials: M
authors.lastname: Mitsunobu
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Kishi
authors.forename: Toshio
authors.initials: T
authors.lastname: Mori
authors.forename: Naoko
authors.initials: N
authors.lastname: Yamada
authors.forename: Koji
authors.initials: K
authors.lastname: Yamanegi
authors.forename: Hideki
authors.initials: H
authors.lastname: Ohyama
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Terada
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ohike
authors.forename: Toshio
authors.initials: T
authors.lastname: Morohoshi
authors.forename: Naoki
authors.initials: N
authors.lastname: Yamanaka
mesh_terms: D018249:Adenoma, Oxyphilic / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D000368:Aged; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary / Q000601:surgery; D046529:Microscopy, Electron, Transmission; D010190:Pancreatic Neoplasms / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D014057:Tomography, X-Ray Computed