Neoplasia, Carcinogenesis Flashcards
how can neoplasias be classified?
- clinical: refers to overall consequences to the host
- histological: benign vs. malignant, can predict clinical behavior
characteristics of benign neoplasia
- expansile growth
- but, contained in capsule
- homogeneous cut surface
characteristics of malignant neoplasia
- invasive growth
- necrosis
- lymphatic invasion
- nonhomogeneous surface
- hemorrhage
- vessel invasion
benign/malignant epithelial tumor
benign: oma
malignant: carcinoma
benign/malignant glandular tumor
benign: adenoma
malignant: adenocarcinoma
benign/malignant mesenchymal tumor
- first of all, this is connective tissue, bone, or muscle origin
benign: oma
malignant: sarcoma
histological classification exceptions
- hematopoietic/lymphoid
- neural
- germ cell
- so, these ones have variable/inconsistent names
are all tumors that end in oma benign?
- no!!
- lymphoma, glioma, seminoma are malignant
blastoma
malignant tumors composed of embryonic/primordia cells
teratoma and teratocarcinoma
- tumors from germ cells, mostly in the testis and ovary, that contain embryonic cells that differentiate into embryonic germ layers - so can have teeth/hair/etc
- teratoma: benign
- teratocarcinoma: malignant
what is the hallmark of malignant cells?
- anaplasia!
- benign cells closely resemble their tissue type of origin (well differentiated)
- malignant cells do not (poorly differentiated)
anaplasia
- lack of differentiated/specific features
- presence of new features that are not inherent to tissue of origin
pleomorphism
variation in cell size and shape
describe anaplastic tumor cells in PAP smear
- pleomorphism
- large, heterochromatic nuclei
- abnormal mitotic figures
tumor staging
- done to predict clinical behavior
- based on clinical exam, x-ray, biopsy, or surgical exploration
international TNM system
- an international staging system!!
- stands for tumor, node, metastasis
- T1, N1, M0: tumor less than 1 inch, spread to 1 lymph node, no metastasis to distant sites
tumor grading
- done to guide therapy
- based on histological exam
- main way to determine benign or malignant nature
- grade I: well differentiated
- grade II: moderately well differentiated
- grade III: undifferentiated (so malignant)
does staging or grading have more prognostic value?
staging! i think this is because it indicates how far the disease has spread, not just what the cells look like?
list 6 hallmarks of cancer
- cancer cells need to acquire traits that enable them to become tumorigenic and ultimately malignant
1. sustained proliferative signaling
2. evading growth suppressors
3. activating invasion and metastasis
4. enabling replicative immortality
5. inducing angiogensis
6. resisting cell death
elaborate on evading growth suppressors
- genome instability generates genetic diversity that expedites the acquisition of these hallmarks
- also underlying these hallmarks is inflammation
- genetic diversity ultimately allows cancer cells to be unaffected by growth suppressors from host?
elaborate on inducing angiogenesis
blood vessels are produced to bring nutrients to cancerous cells
elaborate on resisting cell death
- cancer cells do not undergo apoptosis after a certain amount of cell divisions like normal cells do
- this means they are immortal
- their rate of division may also be unregulated
- the fact that they have nutrients allows this!