[Inflammatory fibroid polyps are true neoplasms with PDGFRA mutations].
OBJECTIVE
Inflammatory fibroid polyps (IFP) are proliferations of CD34-positive spindle cells in the submucosa and mucosa of the gastrointestinal tract with an inflammatory infiltrate. IFP occur in the stomach, small bowel, colon and esophagus. To date, etiology and pathogenesis are unclear.


METHODS
A total of 29 IFP originating in the stomach, small bowel and colon were examined immunohistochemically, and mutational analyses of PDGFRA exons 10, 12, 14 and 18 were conducted.


RESULTS
Activating mutations in PDGFRA exons 12 and 18 were found in 20 cases (69%). The mutational types are related to mutations known from gastrointestinal stromal tumors (GIST). D842V was the most frequent mutation. No activating mutations were found in exons 10 and 14.


CONCLUSIONS
The majority of IFP reveal activating PDGFRA mutations. Our data indicate that IFP are true neoplasms (true benign tumors) and not reactive lesions. In terms of pathogenesis, the relationship between PDGFRA-mutant GISTs and IFP remains to be determined.
Schildhaus
H-U
HU
Institut für Pathologie, Universitätsklinikum Bonn, Sigmund-Freud-Str 25, 53127 Bonn. Hans-Ulrich.Schildhaus@ukb.uni-bonn.de
Büttner
R
R
Binot
E
E
Merkelbach-Bruse
S
S
Wardelmann
E
E
D018952:Antigens, CD34 / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D002471:Cell Transformation, Neoplastic / Q000235:genetics* / Q000473:pathology; D004252:DNA Mutational Analysis; D005091:Exons / Q000235:genetics; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology; D005759:Gastroenteritis / Q000235:genetics* / Q000473:pathology; D005770:Gastrointestinal Neoplasms / Q000235:genetics* / Q000473:pathology; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006104:Granuloma, Plasma Cell / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D007417:Intestinal Polyps / Q000235:genetics* / Q000473:pathology; D008297:Male; D009092:Mucous Membrane / Q000473:pathology; D009361:Neoplasm Invasiveness / Q000473:pathology; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics; D011127:Polyps / Q000235:genetics* / Q000473:pathology; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics*; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology
D018952:Antigens, CD34; D020796:Receptor, Platelet-Derived Growth Factor alpha