A gastrointestinal stromal tumor of the stomach morphologically resembling a neurofibroma: demonstration of a novel platelet-derived growth factor receptor alpha exon 18 mutation.
Gastrointestinal stromal tumors are increasingly being recognized because of their characteristic expression of KIT (CD 117). Most KIT-positive gastrointestinal stromal tumors have activating mutations in the c-kit gene. A subgroup of gastrointestinal stromal tumors are negative for KIT expression, and in these tumors, activating mutations in platelet-derived growth factor receptor alpha are common. Most platelet-derived growth factor receptor alpha mutation-positive gastrointestinal stromal tumors show an epithelioid histology and are located in the stomach. Herein, we describe an unusual gastric stromal tumor. The tumor was negative for KIT expression and the morphology did not show an epithelioid pattern but rather was composed of bland spindle cells reminiscent of a neurofibroma. Molecular analysis revealed a somatic mutation in platelet-derived growth factor receptor alpha exon 18 (D842F). Aside from demonstrating a new platelet-derived growth factor receptor alpha mutation, this case illustrates the usefulness of molecular testing as a diagnostic tool and clearly indicates the wide range of morphology that can be observed in gastrointestinal stromal tumors.
Liu
Ting
T
Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, UT 84132, USA. ting.liu@path.utah.edu
Willmore-Payne
Carlynn
C
Layfield
Lester J
LJ
Glasgow
Robert E
RE
Holden
Joseph A
JA
D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000032:analysis; D003937:Diagnosis, Differential; D005091:Exons; D005260:Female; D005743:Gastrectomy; D046152:Gastrointestinal Stromal Tumors / Q000737:chemistry / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009154:Mutation; D009455:Neurofibroma; D010982:Platelet-Derived Growth Factor / Q000235:genetics*; D016133:Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000235:genetics
D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D010982:Platelet-Derived Growth Factor; C075278:platelet-derived growth factor A