BRAIN TUMORS IN CHILDREN: MORPHOLOGY, IMMUNOHISTOCHEMISTRY, AND MOLECULAR MARKERS IN CLINICAL PRACTICE

Аннотация

This study is aimed at a comprehensive study of the morphological, immunohistochemical, and molecular-genetic characteristics of brain tumors in children. Within the framework of the work, 150 histological samples obtained as a result of neurosurgical operations on children aged 0 to 18 years, conducted at the National Children's Medical Center in 2021-2025, were analyzed. Standard histological studies with hematoxylin and eosin staining, as well as immunohistochemical tests (Ki-67, GFAP, S-100, Olig2, SD34, Synaptophysin or Chromogranin) and molecular studies for IDH1 and BRAF V600E mutations were performed. Most often, pilocytic astrocytomas (34%) and ependymomas (20%) were diagnosed. In most tumors, the expression of GFAP (81%) and Ki-67 more than 10% (48%) was observed. Genetic mutations of IDH1 were detected in 12%, BRAF V600E - in 8% of samples. Analysis of the relationships revealed clear correlations between the immunohistochemical phenotype and the morphological type of tumors. The conclusions contribute to the creation of an algorithm for morphological diagnostics necessary for accurate differentiation of tumors in children and individualization of therapy.