neoplasia Flashcards
neoplasia (def)
persistent abnormal growth of tissue which exceeds and **uncoordinated w/ growth of surrounding normal tissues.
2 defining characteristics of neoplastic cells
- ability to replicate in absence of control by growth factors
- making a mass of new cells with no useful function
3 tumor characteristics like their parent organ
- all have parenchyma (functioning part of tissue) and stroma (supporting part of tissue)
- tumor cells look similar to cells in the organ where tumor arose
- tumor cells perform some of the functions of the parent organ
4 ways tumor characteristics are different from organs
- don’t contribute to body homeostasis
- grow more rapidly than surrounding tissue
- some benign and all malignant tumors never cease to grow (sign of malignancy)
- most tumors show some derangement of histologic architecture (this is dysplasia)
4 characteristics of benign tumors
- cells resemble normals cells and tumor architecture resembles that of the parent organ
- usually are spherical and compress the surrounding tissue
- grow slowly
- never metastasize (spread from primary location to another)
5 characteristics of malignant tumor
- grow more rapidly than benign
- differ morphologically and functionally from normal cells and tumor architecture is less organized than that of parent cell
- locally invasive and grow into surrounding tissue and destroy it
- tumor will metastasize, spreading to another site remote from original tumor (**not all malignant tumors metastasize **exceptions: basal cell skin carcinoma and brain glioma)
- cells resemblance to parent cells will be better or worse depending on whether tumor is “well differentiated” or “poorly differentiated” (more difference = more aggressive)
nomenclature of tumors
ends in “oma”
ends in “carcinoma”
ends in “sarcoma”
- ends in “oma”- usually benign (except melanoma)
- ends in “carcinoma”- epithelial - malignant- lymphatic
- ends in “sarcoma”- mesenchymal - malignant- BV
tumor grades and stages
why stages are assigned - what it’s based on
how grades are assigned- what it’s based on
- stages are assigned to give prognosis and determine treatment - based on how far it spread
- grades are assigned by the cancers degree of differentiation which correlates with how aggressive it is
tumor grades (5)
I- well differentiated (like normal) II - not so well differentated III - worse than grade II (anaplastic) IV - poor differentation (anaplastic) V - not differentiated (anaplastic)
what is anaplastic?
not recognizable/ no resembalance
tumor stages (3)
I - smaller than 1 cm diameter - no metastases
II - larger than 1 cm w/ metastases to regional lymph nodes
III - tumor has infiltrated a deep tissue structure w/ distant metastases
TNM grading system(malignant tumors)
T- tumor (T1-T3)
N- lymph nodes (N0-N2)
M- metastases (M0-M1)
T1: tumor is < 1cm T2: > 1cm T3: invading non-resectable structure N0: no tumor in regional lymph nodes N1: tumor in nearby lymph nodes N2: tumor is in further lymph nodes M0: no distant metastases M1: distant metastases
malignancy
microscopic appearance
histologic diagnosis (what mitoses looks like)
size of malignancy
- increased nuclear DNA, increased nuclear/ cytoplasmic ratio, wrinkled nuclear edges = chaotic and disorganized
- numerous bizarre mitoses that last longer than in healthy tissue
- widely varying sizes with loss of orientation to one another
miotic figure…
def
what it may indicate
when you see it normally
- def- microscopic appearance of a cell undergoing mitosis
- are more likely to be seen in malignant neoplasm.
- normally this number of mitoses can be seen in bone marrow, gonads and GI tract
malignant tumor invasion
local infiltration
“intraepithelial spread”- characteristic of early cancers in wh/ an epithelial surface is replaced by a layer (several cells deep) of malignant tumor which has not yet penetrated the basement membrane
malignant tumor invasion (3)
metastatic spread
- transfer of malignant cells from one site to another not connected with it.
- spread starts with tumor penetration of basement membrane and movement of tumor cells through the surrounding extracellular environment = invasion
- following this malignant cells spread to distant sites by invading lymphatic (carcinomas) or BV (sarcomas)
etiology of cancer (genetic damage)
3 classes of carcinogenic agents
- chemicals
- physical agents (radiation, asbestos)
- oncogenic viruses
etiology of cancer: chemicals basics about the structure indirect vs. direct chemicals mutagen definition what promotors do
- diverse structures including natural and synthetic products
- these chemicals can be direct reacting (need no chemical conversion) or indirect reacting (need metabolic conversion)
- mutagens are highly reactive electrophils that react w/ electron rich atoms in DNA
- in order to express carcinogenicity some of them need agents called promoters
etiology of cancer: chemical carciogenesis
2 steps
multi-step process
- initation- irreversible and usually not detectable by current methods
- promotion- action of second agents that by themselves have little if any cancerous activity
etiology of cancer: chemical carcinogens - indirect acting agents: polycyclic hydrocarbons aromatic amines and AZO dyes alfatoxin nitrosamines metals saccharine and cyclamates
- polycyclic hydrocarbons- originally derived from coal tar and produce cancer at site of application (cigarette smoke)
- aromatic amines and AZO dyes- produce bladder and liver tumors in workers exposed to the aniline dye and rubber industries
- alfatoxin- product of aspergillus flavus and most potent liver carcinogen
- nitrosamines- nitrates used as food preservative may convert to nitrosamines and form liver cancer
- metals- Ni, Cr, Co potential carcinogens in occupational setting
- saccharine and cyclamates- artificial sweeteners in large doses
etiology of cancer: physical
radiation (2)
- radiant energy causes chromosome breakage, translocations and point mutations
- UV rays from sun may cause cancer
etiology of cancer: physical
asbestos (2)
- example of chemical and physically induced tumor
2. tumor is associated with inhalation of asbestos fiber, malignant mesothelioma- from deposition in lung
etiology of cancer: virus RNA retrovirus DNA papilomavirus DNA hep B DNA epstein-barr
- RNA retrovirus- T cell leukemia and lymphoma
- DNA papilomavirus- carcinoma of cervix
- DNA hep B- hepatocellular carcinoma
- DNA Epstein-barr- lymphoma and nasopharingeal carcinoma
systemic effects of cancer- malignant by location
pituitary adenomas
craniopharangiomas
meningeomas
- pituitary adenomas- crushing normal pituitary and optical nerves
- craniopharangiomas- destroy hypothalamus
- meningeomas- compress the brain
systemic effects of cancer- what really kills you/ side effects (4)
- brain damage
- pulmonary edema
- bone fractures
- bowel distruction
systemic effects of cancer- more things it causes cachexia fever hematologic syndromes endocrine syndromes
- cachexia- weakness, malaise, anorexia, wasting
- fever- common in hodgkins lymphoma
- hematologic syndromes- eritrocytosis, anemia, thrombo and granulocytopenia, hemmorage
- endocrine syndromes- production of cortisol, ADH, parathormone, insulin, gonadotropins
