Neoplasia Flashcards
Example of Cells synthesizing their own Growth Factor
Glioblastomas secrete PDGF (platelet derived GF) and express PDGF receptor.
Sarcomas cn make Transforming GF-alpha and its receptor. Autocrine loops.
Ex. Of overexpressed Growth factor receptors
ERBB1, the EGF receptor is over-expressed in 80% of SCC of the lung, and 80-100% of epithelial tumors of the head and neck.
ERBB2/HER2 a related receptor is amplified in 20% of breast cancers.
Siignalling enzyme mutations downstream from growth factor receptors, examples.
RAS and ABL
Example of Transcription factor mutations.
MYC, JUN, FOS are oncogenes that produce oncoproteins which function as transcription factors that regulate expression of growth promoting genes such as cyclins and CDKs.
Ex of precursor lesions
Squamous metaplasia of bronchial mucosa - smokers.
Endometrial hyperplasia- unopposed estrogen stimulation.
Leukoplakia of oral cavity, genitalia- can progress to SCC.
Villous adenoma of the colon- can progress to colorectal carcinoma.
Parenchyma of tumors
Made up of transformed or neoplastic cells. Determines its biologic behavior, derives name from this component.
Stroma
Host derived, supporting tissue of the tumor. Connective tissue, blood vessels, host derived inflammatory cells. Crucial to growth of the neoplasm.
Suffix used for benign tumors
-oma
Adenoma
Tumor arising from glandular epithelia.
Papilloma
Benign neoplasms of epithelia with finger-like projections.
Polyp
Mass that projects above a mucosal surface. Macroscopically visible.
Sarcoma
Malignant tumor of the solid mesenchymal tissues or its derivatives. Designated based on cell type composition, i.e. liposarcoma, chondrosarcoma.
Leukemia/Lymphoma
Cancer arising from the mesenchymal cells of the blood.
Carcinoma
Cancer arising from epithelial cells. They are usually poorly differentiated.
Adenocarcinoma
Carcinomas that grow in a glandular pattern.
Squamous cell carcinoma
Carcinoma that produces squamous cells.
Differentiation (of neoplasms)
Extent to which they resemble their cells of origin, morphologically and functionally. In general benign tumors are well differentiation, malignant tumors are not. However in well differentiated malignant tumors, morphological features may be difficult to spot.
Anaplasia
Lack of cell differentiation.
Pleomorphism
Variation in size and shape of cells and their components. Characteristic of anaplasia.
Nuclear abnormalities
Extreme hyperchromatism, size and shape abnormalities, unusually prominent nucleoli.
Characteristic of anaplasia
Atypical mitoses
May be numerous. Examples like multipolar spindles, asymetry of poles, abnormal chromatid separation or lagging. Characteristic of anaplasia.
Loss of polarity
Cells lack recognizable patterns of orientation to one another. Characteristic fo anaplasia.
well-differentiated tumors
Can often continue normal function, endocrine tumors can continue to produce normal hormones, but possibly at an abnormal rate.
Local invasion
In cancer: Progressive infiltration, invasion, and destruction of surrounding tissues.
In benign tumors: cohesive expansile masses that remain localized.
See: leiomoyoma of myometrium vs. leiomyosarcoma.