International Medicine and Health Sciences Researches Congress, Ankara, Türkiye, 28 - 29 Ağustos 2022, ss.461-462
Objective: PDGFRA mutations are detected rarely in gastrointestinal stromal tumors (GIST), almost always in gastric tumors and mostly related with epithelioid type and low mitotic index. Exon 18-D842V mutations, the frequency of which is reported to be ~6%, constitutes the majority of PDGFRA mutations. In this study, we aimed to determine the frequency and clinicopathological features of PDGFRA-D842V mutated GISTs. Materials and Methods: Among the patients with GIST who underwent PDGFRA mutation analysis with pyrosequencing tecnique between 2016-2022, the cases with Exon 18 D842V mutation were indentified and the clinicopathologic features were examined.Results: Eighty-nine cases with GIST underwent PDGFRA mutation analysis and 4 cases showed PDGFRA Exon 18-D842V mutation (4.5%). Male: female ratio was 1. Median age was 58. All tumors were gastric. Two cases had mixed, one had epitheloid and one had spindle cell morphology. Two tumors showed low risk, two tumors showed high risk features for progression. The tumors with high progression risk exhibited 10th UTSAK, 27-28 August 2022, ANKARA | 462 numerous mitoses with the count of 50/ 5 mm2. All cases but one are alive, being followed and have no sign of recurrence. Conclusion: In our study, the frequency of D842V mutation is detected slightly lower than the literature, which may be due to populational differences. The most striking finding is that this mutation can also be detected in tumors with high progression risk and intense mitotic activity.
Keywords: Gastrointestinal Stromal Tumor, Pdgfra Mutation, D842v Mutation