title: Morphology and genetics of pyloric gland adenomas in familial adenomatous polyposis.
abstract: OBJECTIVE
  Gastric pyloric gland adenomas (PGAs) are rare epithelial polyps that are found more commonly in autoimmune atrophic gastritis and familial adenomatous polyposis (FAP). Little is known about the morphology and genetics of PGAs in FAP. PGAs in FAP are studied morphologically and genetically. Findings in FAP-associated PGAs are compared to sporadic PGAs and related lesions such as oxyntic gland adenoma (OGA) to increase our understanding of these rare polyps.
  
  
  RESULTS
  Seven PGAs and 18 fundic gland polyps (FGPs) from FAP patients were collected. KRAS and GNAS mutations were determined in six PGAs and 18 FGPs. Immunohistochemistry was applied on five PGAs to provide further confirmation of the histological subtypes and genetic alterations. Morphology of all PGAs was studied and compared to literature on sporadic PGAs and related lesions. All successfully sequenced PGAs (six of six) carried GNAS mutations and half of the successfully sequenced PGAs carried a KRAS mutation (three of six). Nuclear β-catenin was seen only in one PGA with focal high-grade dysplasia. Morphologically, PGAs in FAP showed overlapping features with OGA.
  
  
  CONCLUSIONS
  Familial adenomatous polyposis-associated PGAs have a similar genetic background as sporadic PGAs, i.e. KRAS and GNAS mutation. Based on morphological findings in FAP associated PGAs, it is hypothesized that PGAs and OGAs are closely related lesions.
authors: Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands.|Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Wenzel M
authors: WM
authors: Hackeng
authors: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Elizabeth A
authors: EA
authors: Montgomery
authors: Departments of Medicine, Oncology Center and Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Francis M
authors: FM
authors: Giardiello
authors: Department of Pathology, University of Pittsburgh, Pittsburgh, PA, USA.
authors: Aatur D
authors: AD
authors: Singhi
authors: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Marija
authors: M
authors: Debeljak
authors: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: James R
authors: JR
authors: Eshleman
authors: Institut für Pathologie, Klinikum Bayreuth GmbH, Bayreuth, Germany.
authors: Michael
authors: M
authors: Vieth
authors: Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors: G Johan
authors: GJ
authors: Offerhaus
authors: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Laura D
authors: LD
authors: Wood
authors: Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands.|Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Lodewijk A A
authors: LA
authors: Brosens
mesh_terms: D000236:Adenoma / Q000235:genetics* / Q000473:pathology*; D011125:Adenomatous Polyposis Coli / Q000235:genetics / Q000473:pathology; D000328:Adult; D000368:Aged; D002864:Chromogranins / Q000235:genetics; D004252:DNA Mutational Analysis; D005260:Female; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000235:genetics; D005753:Gastric Mucosa / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology*; D055815:Young Adult
chemical_list: D002864:Chromogranins; C117307:KRAS protein, human; C406732:GNAS protein, human; D019205:GTP-Binding Protein alpha Subunits, Gs; D016283:Proto-Oncogene Proteins p21(ras)
keywords: familial adenomatous polyposis; fundic gland polyp; gastric adenoma; oxyntic gland adenoma; pyloric gland adenoma