title: Intrahepatic peribiliary perivascular epithelioid cell tumor (PEComa) associated with heterotopic pancreas: A case report.
abstract: BACKGROUND
  Perivascular epithelioid-cell tumor (PEComa) is a group of rare mesenchymal neoplasms that express myomelanocytic-cell markers and exhibit a wide variety of histopathological features. Although heterotopic pancreas has been reported to occur in the gastrointestinal tract, intrahepatic heterotopic pancreas has been reported only rarely.
  
  
  METHODS
  We present a case of intrahepatic PEComa that showed a strong regional correlation with the presence of heterotopic pancreas. An intrahepatic tumor and biliary dilatation was incidentally discovered during a diagnostic evaluation to investigate low-back pain in a 47-year-old Japanese male. Cholangiocarcinoma was suspected and a left hemihepatectomy performed. Histological examination revealed a 3 × 3.8-mm tumor in the neighboring B2 bile duct. Histological and immunohistochemical investigations revealed the presence of a PEComa and pancreatic acini within the tumor mass. PEComa in the hepatobiliary and pancreatic regions are extremely rare. The presence of heterotopic pancreas is also relatively uncommon.
  
  
  CONCLUSIONS
  The strong regional association of these 2 lesions raises the possibility of a PEComa originating from heterotopic pancreas or from an irritable response caused by heterotopic pancreas.
authors.affiliation: Department of Diagnostic Pathology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kiriyama
authors.affiliation: Department of Diagnostic Pathology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan. ttsukamt@fujita-hu.ac.jp.
authors.forename: Tetsuya
authors.identifier: http://orcid.org/0000-0002-7502-8724
authors.initials: T
authors.lastname: Tsukamoto
authors.affiliation: Department of Diagnostic Pathology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Mizoguchi
authors.affiliation: Department of Surgery, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Ishihara
authors.affiliation: Department of Surgery, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Horiguchi
authors.affiliation: Department of Surgery, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
authors.forename: Takamasa
authors.initials: T
authors.lastname: Tokoro
authors.affiliation: Department of Surgery, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Department of Surgery, Fujita Health University School of Medicine, Toyoake, Aichi, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sugioka
authors.affiliation: Department of Diagnostic Pathology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kuroda
mesh_terms: D001650:Bile Duct Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D001653:Bile Ducts, Intrahepatic / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D014408:Biomarkers, Tumor / Q000032:analysis; D049448:Cholangiopancreatography, Magnetic Resonance; D002828:Choristoma / Q000175:diagnosis; D006498:Hepatectomy; D006801:Humans; D007150:Immunohistochemistry; D033162:Incidental Findings; D008107:Liver Diseases / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D010179:Pancreas; D010190:Pancreatic Neoplasms; D054973:Perivascular Epithelioid Cell Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor
keywords: Heterotopic pancreas; Liver; Perivascular epithelioid cell tumor (PEComa)