title: Activating PDGFRA mutations in inflammatory fibroid polyps occur in exons 12, 14 and 18 and are associated with tumour localization.
abstract: OBJECTIVE
  Inflammatory fibroid polyps (IFP) are mesenchymal tumours of the gastrointestinal tract. This study was performed to broaden the base of evidence of the pathogenic role of PDGFR mutations in IFP with particular regard to clinicopathological data and mutational patterns among IFP subtypes.
  
  
  RESULTS
  Molecular analysis of 38 tumours revealed activating mutations in three different exons of PDGFRA in 25 IFP. For the first time we report two cases with PDGFRA-exon 14 mutations (p.N659K; p.[N659K(+)T665A]). The results of our study and cases reported earlier indicate clearly that there is a localization-specific pattern: exon 12 mutations predominate in the small intestine, while exon 18 mutations occur frequently in the stomach (P < 0.001). Codons 567-571 of PDGFRA represent an IFP specific mutational hot spot and are affected most frequently by deletions. Furthermore, in our series IFP of the stomach share common features. In contrast to intestinal IFP, gastric tumours occur at higher age, show heavy inflammation and tend to be smaller. IFP located in the small intestine are frequently associated with intussusception.
  
  
  CONCLUSIONS
  We conclude that there is a 'small bowel' and a 'gastric' phenotype of IFPs which are associated with exon 12 and exon 18 PDGFRA mutations, respectively.
authors.affiliation: Institute of Pathology, University of Cologne Medical Center, Cologne, Germany             Institute of Pathology, University of Bonn Medical Center, Bonn, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Huss
authors.forename: Eva
authors.initials: E
authors.lastname: Wardelmann
authors.forename: Diane
authors.initials: D
authors.lastname: Goltz
authors.forename: Elke
authors.initials: E
authors.lastname: Binot
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hartmann
authors.forename: Sabine
authors.initials: S
authors.lastname: Merkelbach-Bruse
authors.forename: Reinhard
authors.initials: R
authors.lastname: Büttner
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Schildhaus
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000032:analysis; D005091:Exons / Q000235:genetics*; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007417:Intestinal Polyps / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D020796:Receptor, Platelet-Derived Growth Factor alpha