The structure and biologic properties of malignant tumors
The structure and biologic properties of malignant tumors - Malignant tumors distinguish themselves from the tissues where they occur with: structural changes, blokimiawi and functional, often accelerated growth, infiltrative growth, and ability to form metastases. These properties are determined by changes in the tumor cells themselves, the general state of the local and outside the tumor.
Structural changes.
Tumor composed of cells in many different morphologic slightly from the cells in the organ where the occurrence of malignant transformation. In these cells are not obtained a high differentiation and orderly arrangement of the nature of the abnormal tissue.
These changes are often called 'de-differentiation', but the term is actually a misnomer. Because this would mean that this malignant transformation occurs in cells that have a high differentiated and de-differentiation then occurs. We know that tumors originating in 'reserve cells' 'or' 'stem cells' undifferentiated, and after it happens differentiation in different levels.
Sometimes a high level of differentiation such that practically achieved network structure of origin. In tumors of low differentiation almost nothing in common with their home network. This is often not possible origin of the tumor revealed it, and we are dealing with an anaplastic tumor.
Nomenclature of tumors based on differentiation histologiknya. Called epidermoid carcinoma if there is a real differentiation in the direction of stratified squamous epithelium, such as pertandukan formation and the formation of cytoplasmic bridges (plasmodesmen). Adenocarcinoma is a carcinoma with glandular structure leads to a form. So this does not depend on the cell type from which the tumor was.
In addition anaplasia, tumor cells still showed some rather specific morphologic properties. The point is usually large, and show real differences in shape and size (poly or pleomorfi). Nucleic acid levels in the nucleus are often high, making it easier stained with dyes such as hematoxylin base (hiperkhromasi).
Distribution in the core khromatin rough. Often nucleoli increased in number and larger than the nucleoli of cells that are not malignant. Most of these changes can be restored to the irregular distribution of DNA into daughter cells during cell mitosis.
Regarding khromosomnya this pattern often resulted in an tetraploidi and polyploidy (chromosome number several times a haploid number) or aneuploidy (an additional amount that is typical khromosomal ('marker chromosomes'') is known only in some malignancies (Philadelphia chromosome in chronic myeloid lekemi). Perhaps changes in patterns of chromosomes as the only large bandwagon phenomenon and not the main cause of the abnormal properties.