Benign neoplastic cells resemble the normal morphology of the cell of origin. What are malignant neoplastic cells characterized by (7)?
Cellular & Nuclear Pleomorphism (due to alterations in the cell cytoskeleton)
Increased Nuclear/Cytoplasmic Ratio
Increased Nuclear Chromatin (which is frequently "clumped" along an irregular nuclear membrane)
Large Nucleoli
Bizarre Mitoses
Loss of Cellular Orientation
Loss of Normal Functional Capacity
Lack of differentiation
Aplasia
This refers to the extent to which neoplastic cells resemble their cell of origin histologically
Cellular Differentiation
True or False:
Cells of benign neoplasms are well differentiated, have a normal number of chromosomes, and retain functional capabilities
True
True or False:
Malignant cells show abnormalities in the number and structure of chromosomes and, within the same tumor, may vary from complete lack of differentiation to well differentiated
True
Compare the growth rate of benign vs malignant neoplasms
Benign grow slow and may regress; malignant grow more rapidly and rarely regress
Which type of neoplastic cells, benign or malignant, grow by expansion and tend to compress the surrounding tissue into a "capsule" that separates the tumor from normal tissue?
Benign
Which type of neoplastic cell, benign or malignant, grow by infiltration and invasion of the surrounding tissue and are not confined by a capsule?
Malignant
The spread of a neoplasm to points that are not contiguous with the primary lesion
Metastasis
The most common route of metastasis, especially of epithelial neoplasms (carcinomas). Follows the natural lymphatic drainage of the site of malignancy.
Lymphatic Dissemination
This route of metastasis is characteristic of connective tissue neoplasms (sarcomas). Carcinomas can also spread by this route, however. Invasion and metastasis are more likely to occur via the venous system (as opposed to the arterial system) due to its thin walled structure
Hematogenous Dissemination
This route of metastasis may occur with malignancies that involve coelomic surfaces
Transcoelomic Seeding
In this type of metastasis, excessive manipulation or cutting into malignant tumors may detach and carry small portions of the tumor to other sites
Traumatic Seeding
Excessive production of connective tissue
Desmoplasia
True or False:
Benign neoplasms are more prone to infarction, necrosis hemorrhage, ulceration, and infection
False--> malignant neoplasms are
Some tumors (benign or malignant) may produce hormones or hormone-like substances that can have systemic effects known as ______?
True or False:
The carcinogenicity of various chemical agents appears to be dose dependent so that multiple fractional doses over time have the same transforming potential as a comparable one-time dose
True
When two or more different chemicals act synergistically to induce cell transformation is is called _____?
Co-Carcinogenesis
How are most known carcinogens metabolized?
By cytochrome P450-dependent mono-oxygenases in the liver
What are the four steps of transformation of a normal cell to a neoplastic cell?
Initiation
Promotion
Conversion
Progression
This may directly ionize critical cellular macromolecules or interact with cellular water to produce free radicals that mediate cellular damage by breaking or altering chemical bonds. Its ability to induce neoplastic transformation appears to correlate best with its ability to induce genetic mutation within the cell
Ionizing Radiation
Through the process of transduction and insertional mutagenesis, these may directly rearrange the structure or alter the expression of the host cell genome. In order to be transformed the host cell must survive and be able to reproduce.
Viruses
What are the major features of neoplastic cells (8)?
Increased rate of stem cell renewal
Loss of contact inhibition
Anchorage independent growth (do not require attachment to hard surface to proliferate)
Less Cohesive
Require fewer exogenous growth factors
Immortal (Cell lines can be kept alive indefinately)
Can develop invasive properties
Have metastatic potential
True or False:
Most tumors are of monoclonal origin i.e., a single cell from normal or preneoplastic tissue becomes neoplastic at a specific layer of differentiation and the clonal derivatives of that cell produces the neoplasm
True
The proportion of cells within a tumor population that are in the proliferating pool. The rate of tumor growth depends upon this and the degree of imbalance between cell production and cell loss. This has a profound effect upon a tumor's susceptibility to chemo. High = most vulnerable to cancer drugs
Growth Factor (GF)
These factors, which induce fibrinogen and various substances produced by the tumor cells, promote and control the neovascularization of the expanding cell mass. The neovasculature tends to be abnormal due to loose endothelial junctions
Angiogenic Factors
True or False:
A greater degree of angiogenesis within a tumor is correlated with a more aggressive behavior and poorer prognosis
True
Clumps of ______ tumor cells appear more effective at producing metastases than either single cells or multiple clumps
5-10
True or False:
Fewer than one in a thousand tumor cells released into the bloodstream will ultimately metastasize
