text: Epithelioid gastrointestinal stromal tumor with PDGFRA activating mutation and immunoreactivity.
  The authors report a unique case of an intra-abdominal, epithelioid mesenchymal tumor that had an activating mutation of PDGFRA and a strong PDGFRA immunoreactivity but lacked both c-kit mutation and c-kit protein (CD117) expression. IHC study showed that the tumor cells were diffusely and strongly positive for PDGFRA, vimentin, CD34, and Bcl-2 but completely negative for CD117 as well as for muscle, epithelial, endothelial, endocrine, mesothelial, neural, and melanocytic cell markers. Molecular study revealed a mutation at the juxtamembrane domain of exon 12 in PDGFRA gene with GTC to GAC transition at codon 561 (V561D), as shown in the previous mutational studies on gastrointestinal stromal tumor (GIST). This case likely represents an example of GIST with PDGFRA activating mutation and PDGFRA immunoreactivity without CD117 positivity, which has not been documented in the literature. STI 571 (imatinib mesylate [Gleevec]) might be an effective therapy in this case, since Gleevec targets both PDGFRA and c-kit oncoproteins.
entities.id: T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T1 T20 T21 T22 T23 T2 T3 T4 T5 T6 T7 T8 T9
entities.type: GENE-Y GENE-Y GENE-Y GENE-Y GENE-Y GENE-Y GENE-Y GENE-Y GENE-N GENE-N CHEMICAL GENE-Y GENE-Y GENE-Y GENE-Y CHEMICAL CHEMICAL CHEMICAL GENE-Y GENE-Y GENE-Y GENE-Y GENE-Y
entities.text: c-kit CD117 PDGFRA vimentin CD34 Bcl-2 CD117 PDGFRA GTC to GAC V561D STI 571 PDGFRA PDGFRA CD117 PDGFRA imatinib mesylate Gleevec Gleevec PDGFRA c-kit PDGFRA PDGFRA c-kit