Determination of muscle differentiation markers SMA and MSA in CD117-positive and CD117-negative gastrointestinal stromal tumors of different malignant potential

Aim. To determinate the muscle differentiation markers SMA and MSA in CD117-positive and CD117-negative gastrointestinal stromal tumors of different malignant potential. Mеthods and results. Gastrointestinal stromal tumors (GIST) require a thorough differential diagnosis with smooth muscle tumors (benign and malignant) of the gastrointestinal tract. In order to determine the relationships between the clinical (age, localization of the primary tumor) and morphological (histological type of structure, expression of markers of histogenesis - CD117 and proliferative activity - Ki-67) characteristics of GIST and expression of markers of muscle differentiation we studied character of coloring SMA, MSA in the 47 cases (immunohistochemical method). Сonclusion. It was established, that MSA-positive GIST were found in 6.4%. Distribution of SMA-positive cases in groups with different clinical and morphological characteristics is similar. In our study, we found no prognostic value of the marker SMA, although samples with high levels of expression of marker Ki-67 are more common among SMA-positive cases (p> 0.05).