Morphological studies represent the most important part of evidence-based medicine, and in oncology they are an essential attribute in the diagnostics of malignant neoplasms. In experimental oncology, current models of the tumor growth are developed to be as close as possible to the actual biological life conditions. There is a need to study the pathogenesis of tumors in various variants of their orthotopic growth, the formation of bi-model systems with a combination of the malignant growth and comorbid conditions (chronic neurogenic pain, diabetes mellitus, hypothyroidism, obesity), the use of subcellular substrates for the induction of carcinogenesis and biotherapy. Among the important methods for studying the pathogenesis of tumors, morphology is on a par with advanced molecular genetic and biochemical methods, as well as radioimmunoassay techniques.Morphological studies represent the most important part of evidence-based medicine, and in oncology they are an essential attribute in the diagnostics of malignant neoplasms. In experimental oncology, current models of the tumor growth are developed to be as close as possible to the actual biological life conditions. There is a need to study the pathogenesis of tumors in various variants of their orthotopic growth, the formation of bi-model systems with a combination of the malignant growth and comorbid conditions (chronic neurogenic pain, diabetes mellitus, hypothyroidism, obesity), the use of subcellular substrates for the induction of carcinogenesis and biotherapy. Among the important methods for studying the pathogenesis of tumors, morphology is on a par with advanced molecular genetic and biochemical methods, as well as radioimmunoassay techniques.