Introduction. The rapid development of basic science enabled us to significantly expand our understanding of various intercellular interactions. Epithelial-mesenchymal transition (EMT) is known to play a key role in certain tissue formation in the embryonic period. However, recent data show that EMT can also be observed in some pathological conditions, in particular, in various neoplasm development. This suggests that there are a number of alternative and fundamentally new mechanisms for the tumor formation and progression. Thus, EMT, which occurs in carcinomas, increases the invasiveness, immunoresistance, immunity to therapy, and the metastatic potential. Knowledge of EMT features and their timely recognition in morphological tumor diagnosis is of great predictive importance for patients. The aim of the research was to study the morphologi-cal features of epithelial-mesenchymal transition in the main types of gastric cancer. Materials and methods. We studied specimens of gastric carcinomas (N=64) including 31 cases of diffuse type, 19 cases of intestinal type, and 14 cases of mixed type. Results. All cases of the diffuse carcinoma group showed spread EMT features, which appeared already in the mucosa and completed with positive vimentin expression in 93.5% of cases. The malignant cell prolifera-tive activity was low; however, in 29% of cases we detected areas of moderate or even high activity. In the intestinal type gastric cancer, EMT developed as a result of tumor progression, it arose more often in the deeper layers and was incomplete and focal. As a rule, the proliferative activity of tumor cells was high and moderate. Vascular invasion occurred more often in diffuse type (90.3%), less often in mixed type (71.4%), and even less often in the intestine type (55.8%) gastric carcinoma. Conclusion. The variety of morphological features of EMT, its frequency, prevalence, completeness, and sequence in the development of various types of gastric cancer determines the features of their clinical manifestation and influences their further management. Keywords: gastric cancer, diagnosis, histological main types, EMT, morphopathology
S3172 Mixed Type Gastric Adenocarcinoma Presenting as Acute Gastric Perforation in a Young Adult: Can Crack Cocaine Cause Early Onset Perforation or Gastric Carcinoma Itself?
