Skoryk V. Histopathological and immunohistochemical characteristics of gastrointestinal stromal tumors

The thesis is devoted to study the diagnostic and prognostic value of morphological features and immunohistochemical (IHC) markers expression for GIST by determining the frequency of occurrence (FO) these parameters and establishing relations between them and between them and clinical data. The histological features and immunophenotype of GIST with different morphological type and site was clarified first. The main diagnostic morphological characteristics may be considered the presence of dystrophic and sclerotic changes of the stroma (FO 74,75%), spindle cell type (FO 54,55%), paranuclear vacuoles (FO 45,45%) or lack of pronounced polymorphism (FO 95,96%) giant single- and multinuclear cells (FO 76,77%), myxoid stroma (FO 70,71%). The need to use for diagnosing GIST as the primary panel next ICH markers: CD117, DOG1, CD34, SMA, MSA, S100, desmin and as additional diagnostic characteristics: coloring of PDGFR? and p21WAF1 was confirmed by statistically (p> 0.05 for all search performance predictability nature of expression of each of these markers). The need to consider the availability of histological structural features (cellularity (p <0.01)) and expression of imunohistochemical markers (Ki-67 (p <0.001) p16ink4A (p <0.05)) for determining the risk of malignant behavior of GIST we statistically proved too.