title: A case of nonfunctioning pancreatic endocrine tumor with atypical imaging findings due to prominent fibrosis of the tumor stroma.
abstract: The patient, a 56-year-old woman, was found during routine checkup to have a disorder of hepatic function. Abdominal ultrasonography showed an ill-defined hypoechoic mass in the head and body of the pancreas; however, no blood-flow signal was observed within the tumor on Doppler ultrasonography. Abdominal computed tomography showed a low-density area in the arterial and portal venous phases. The lesion was visualized as an area of low signal intensity on both T1- and T2-weighted magnetic resonance images, whereas fluorodeoxyglucose positron emission tomography showed fluorodeoxyglucose accumulation in the tumor. Although a preoperative diagnosis was difficult to make, a rapid cytologic examination revealed evidence of a pancreatic endocrine tumor, and subtotal stomach-preserving pancreaticoduodenectomy with portal vein resection was performed. Histopathological examination showed tumor cell nests scattered in abundant fibrotic tissue; the tumor cells had proliferated in a cord-like fashion and showed immunostaining for chromogranin A. Staining for fibroblast activation protein α was seen in the fibroblastic cells contained within the fibrous stroma surrounding the tumor cell nests, whereas both the fibroblastic cells in the tumor and those in the stroma showed a high rate of staining for thrombospondin. We presume that tumor-associated fibroblasts were involved in the fibrosis of the tumor stroma.
authors.affiliation: Institute of Gastroenterology, Nippon Medical School Musashi Kosugi Hospital.
authors.forename: Arichika
authors.initials: A
authors.lastname: Hoshino
authors.forename: Takayuki
authors.initials: T
authors.lastname: Aimoto
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Suzuki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Mizutani
authors.forename: Hideaki
authors.initials: H
authors.lastname: Ishii
authors.forename: Keisuke
authors.initials: K
authors.lastname: Mishima
authors.forename: Yudai
authors.initials: Y
authors.lastname: Wada
authors.forename: Seiji
authors.initials: S
authors.lastname: Kuroda
authors.forename: Aki
authors.initials: A
authors.lastname: Yagi
authors.forename: Takao
authors.initials: T
authors.lastname: Shimizu
authors.forename: Rina
authors.initials: R
authors.lastname: Oyama
authors.forename: Ryo
authors.initials: R
authors.lastname: Yamagiwa
authors.forename: Seiichi
authors.initials: S
authors.lastname: Satoh
authors.forename: Hidemi
authors.initials: H
authors.lastname: Oba
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Shibuya
authors.forename: Eiji
authors.initials: E
authors.lastname: Uchida
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D019002:CD56 Antigen / Q000378:metabolism; D053379:Chromogranin A / Q000378:metabolism; D003952:Diagnostic Imaging / Q000379:methods*; D010450:Endopeptidases; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology*; D005355:Fibrosis; D018093:Gelatinases / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000378:metabolism; D008875:Middle Aged; D010179:Pancreas / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000601:surgery; D016577:Pancreaticoduodenectomy / Q000379:methods; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D012697:Serine Endopeptidases / Q000378:metabolism; D019699:Thrombospondins / Q000378:metabolism; D000099167:Fibroblast Activation Protein Alpha
chemical_list: D014408:Biomarkers, Tumor; D019002:CD56 Antigen; D053379:Chromogranin A; D010450:Endopeptidases; D018093:Gelatinases; D008565:Membrane Proteins; D010751:Phosphopyruvate Hydratase; D012697:Serine Endopeptidases; D019699:Thrombospondins; D000099167:Fibroblast Activation Protein Alpha