Characteristics of malignant tumors Flashcards
What are histologic characteristics of malignant neoplasms?
Enlarged nuclei with nucleus/cytoplasm (N/C)
Hyperchromasia - darkly staining ( DNA)
Coarsely clumped chromatin
Prominent nucleoli, maybe multiple
Increased number of mitoses, some abnormal
What are characteristics of malignant neoplasms?
Differentiation and Anaplasia
Rate of growth
Local invasion
Distant metastasis: most important criteria of malignancy
What is differentiation?
the extent to which parenchymal cells resemble comparable normal cells, both morphologically and functionally.
What is anaplasia?
lack of differentiation
What does benign tumors usually resemble?
virtually the same as the cell or tissue of origin
has a unique (cell culture-like) uniformity of cell appearance.
What are neoplasm that closely resemble their normal cell of origin?
well differentiated
What are moderately differentiated neoplasms?
clearly malignant, but easily resemble their cell of origin
What are poorly differentiated cells?
Neoplasms that hardly resemble their cell of origin
What is dysplasia?
represents disordered cell proliferation
What is a pre invasive neoplasm/carcinoma?
disordered cell proliferation, and when these changes are severe without penetration of the basement membrane
What neoplasm have the higher growth rate?
malignant
What affects the growth rate of neoplasms?
hormone dependence, adequacy of blood supply, “genetics”, etc., influence growth.
What is metaplasia?
REVERSIBLE change in which one adult cell type ( epithelial or mesenchymal ) is replaced by another adult cell type.
What is pleomorphism?
variation in size & shape.
What does most benign tumors grow as?
tumors grow as cohesive expansile masses and remain localized.
They develop a rim of compressed connective tissue, a fibrous capsule, a discrete, easily movable mass.
