Epithelial Neoplasia Flashcards
What is skin?
- largest organ
- covers all external surfaces
- many layers
> epidermis
> dermis - supporting fibrous layer
What is mucosa?
- lines all cavities which connect with outside of body (GI tract, genitourinary tract, respiratory tract)
- layers:
> epithelium
> lamina propria - supporting fibrous layer - may be keratinized or not depending on location
What’s the difference between epithelium and epidermis?
- epidermis is found on skin (external) and epithelium is found on external surface of mucous membranes only
- both are avascular
What are melanocytes?
- dendritic
- attach to basement membrane via hemidesmosomes
- neural crest origin
- produce melanin which is transported by phagocytosis
What are Langerhan’s cells?
- dendritic
- not attached to epithelial cells
- located in stratum spinosum
- phagocytic
- have MHC Class II molecules
- antigen presenting
Describe the three main types of oral mucosa.
Lining mucosa - sacrifices surface toughness for flexibility
Masticatory mucosa - well keratinized and adapted for heavy masticatory frictional forces
Specialized mucosa - compelx surface to support taste buds, maximize flexibility and resist masticatory forces
_______ means neoplasms in which the cells do not metastasize. Still able to cause local destruction if they extend into and compromise vital structures.
Benign
_____ refers to neoplastic cells which are so poorly differentiated that is is impossible or difficult to determine the tissue of origin.
Anaplasia
_______ means “new growth.” May be benign or malignant neoplasms that arise from a single cell which has changed significantly, to permit it to proliferate in an autonomous fashion; does not respond to the normal growth regulatory mechanisms
Neoplasm
___________ refers to histologically evident alterations of epithelial cells which correlate with an increased potential for malignancy
Epithelial dysplasia
_____ is the detachment of neoplastic cells from the original growth site and migration to other sites. The cells usually migrate through the lymphatic system or the blood vessels.
Metastasis
_____ neoplasms which have a potential for metastatic spread. Usually more aggressive in growth and are more likely to result in death.
Malignant
________ describes the degree to which the neoplastic cells resemble the cells in the “normal” parent tissue. A well-differentiated neoplasm has a high degree of resemblance.
Differentiation
Describe the model of carcinogenesis.
- increasing accumulation of genetic damage with time - results in the release of the cell from the normal constraints governing cell proliferation
- genetic damage from various sources targets oncogenes causing unrestrained clonal proliferation
What are the histologic attributes of a cancer cell?
- nuclear hyperchromatism
- nuclear and cellular pleomorphism
- altered nuclear/cystoplasmic ratio
- increase and abnormal mitotic figures
What is grading?
describing the extent to which a malignant tumor has differentiated to resemble the parent tissue from which the tumor arose.
- assigned various grades (1,2,3) or verbally described (well, moderate, poorly differentiated)
- typically a well differentiated tumor is better than a poorly differentiated one
What is staging?
a clinical decision describing the extent to which a malignancy has spread. Usually the size of the tumor, whether it has crossed natural anatomic barriers and whether it has mestasized.
- assigned stage 1-4, 4 being the worst
How do you name a benign tumor?
- prefix indicates originating tissue
- suffix is “oma”
How do you name a malignant tumor?
- tumor usually grouped into one major category depending on originating tissue:
> epithelium: carcinoma
> mesenchymal: sarcoma
> hematopoeietic: lymphoma, leukemia, myeloma
Name type and location of cancer: liposarcoma
fat, malignant
Name type and location of cancer: osteoma.
bone, benign
Name type and location of cancer: leimyosarcoma
muscle, malignant
Name type and location of cancer: chondroma
cartilage, benign
Name type and location of cancer: verrucous carcinoma
lining epithelium, malignant
