title: A primary pure pancreatic-type acinar cell carcinoma of the stomach: a case report.
abstract: BACKGROUND
  Acinar cell carcinoma represents only 1-2% of exocrine pancreatic neoplasms. On exceptionally rare occasions, primary acinar cell carcinoma can occur in ectopic locations. Herein, we report a case of pure pancreatic-type acinar cell carcinoma arising in the stomach.
  
  
  METHODS
  A 54-year-old male presented with a gastric submucosal mass detected by endoscopic examination. Laparoscopic wedge resection was performed. Macroscopically, the 2.7 cm yellowish mass was located in the submucosa of the stomach. Microscopically, the tumor was well circumscribed and had a homogeneous acinar architecture. The tumor cells were small and had a minimal amount of cytoplasm. The nuclei of the tumor cells were round to oval with finely dispersed chromatin. The tumor cells were strongly positive for α1-antitrypsin, chymotrypsin, and α1-antichymotrypsin immunostaining, consistent with pancreatic exocrine differentiation. There was no clinical or radiologic evidence of primary pancreatic or head and neck tumors. After surgical resection of the tumor, there was no recurrence or metastasis during 33 months follow-up.
  
  
  CONCLUSIONS
  In this report, we have presented a rare case of primary pure pancreatic-type acinar cell carcinoma arising in the stomach and suggest that it could be helpful if the pathologist were aware that pancreatic-type acinar cell carcinoma could arise in the stomach as a polypoid submucosal tumor in the routine diagnostic field of gastric endoscopy.
authors.affiliation: Department of Pathology, Chonbuk National University Medical School, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital and Research Institute for Endocrine Sciences, 567 Baekje-daero, Dukjin-gu, Jeonju, 561-756, Republic of Korea.
authors.forename: Kyoung Min
authors.initials: KM
authors.lastname: Kim
authors.affiliation: Department of Surgery, Chonbuk National University Medical School, Jeonju, Republic of Korea.
authors.forename: Chan Young
authors.initials: CY
authors.lastname: Kim
authors.affiliation: Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
authors.forename: Seung-Mo
authors.initials: SM
authors.lastname: Hong
authors.affiliation: Department of Pathology, Chonbuk National University Medical School, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital and Research Institute for Endocrine Sciences, 567 Baekje-daero, Dukjin-gu, Jeonju, 561-756, Republic of Korea. kyjang@chonbuk.ac.kr.
authors.forename: Kyu Yun
authors.initials: KY
authors.lastname: Jang
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D018267:Carcinoma, Acinar Cell / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor
keywords: Acinar cell carcinoma; Heterotopic pancreas; Stomach