Organ location and classification of neoplasms: Pathomorphology, clinical prognosis and basics of treatment

Abstract

The study describes the organ location of neoplasms, their classification, karyotypic and phenotypic changes and biomarkers. The majority of neoplasms mentioned in the study behave typically in their local growth, infiltration and destruction of neighboring tissues, recurrence and metastasis. Nonetheless, numerous exceptions from that rule are noted. The study discusses the process of the formation of monoclones in malignant tumors, especially in lymphomas. The phenotypic markers of differentiation have been useful in the classification of neoplasms. Neoplastic differentiation begins at the molecular level, which is reflected in the phenotype of the cells, and the direction of differentiation usually corresponds to the initial tissue. The neoplastic cell genome is unstable and susceptible to mutation, which may also be influenced by viruses that change the genetic code. This affects the cell cycle and results in proliferation prevailing over necrosis and apoptosis. The karyotypic changes in neoplastic cells are transmitted from generation to generation; they are irreversible and progressive. Moreover, these cells, as compared to normal cells, show higher resistance to various stress factors, which may play an important role in their progression to a malignant phenotype. It has been shown that malignant neoplasms express the whole range of malignant characteristics, although this feature is not constant and may be influenced by the genetic instability of the cells, by the microenvironment and/or by the treatment.