patho chapter 7

neoplasm:

irreversible because its autonomous

dysplasia:

reversible because its a result of a stimulus

beging tumor:

* Slow and orderly growth 
* Growth by expansion
* Does Not invade 
* Localized 
* Resemble normal cells 

Adenoma:

* from glandular epithelium 
* benign

Angioma:

* from blood vessels 
* benign

Chondroma:

* from cartilage 
* benign

Polyps or papilloma:

* on a stalk arising from an epithelial surface
* benign

Malignant tumor:

* Rapid and disordered growth 
* Invades surrounding tissues 
* Cells are poorly differentiated and immature 

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Carcinoma:

* involves epithelial tissue 

Sarcoma:

* arising from any tissue other than epithelium or blood 

Chondrosarcoma:

* cartilage

Liposarcoma:

adipose 

Leukemia:

neoplasm of blood cell

how tumors form from a single cell:

* Start from single cells that have damage s its genome, causing proliferate abnormally


* Clone of identical cell is formed, if not checked can turn into tumor 
* Doesn’t respond to normal growth regulatory singles 
* Secrete enzymes that break down normal cells and tissue barriers

tumors and blood supply:

* Tumors derive blood supply from tissue they invade 
* Malignant tumors frequently induce new blood vessels to proliferate in adjacent normal tissues to supply the demands of the growing tumor 

Necrosis:

malignant tumor may outgrow its blood supply

carcinoma in situ:

carcinomas arisiisng rom the surface epithlium remain localized within the epithlium fro many years

where can carcinoma in situ occur:

* cervix 
* Breast 
* Urinary tract 
* Colon 
* Skin 


* Can be completely cured by surgical excision or treatment that eradicated abnormal epithelium 

precancerous condition:

* Nonmalignant condition with a tendency to become malignant 
* Precancerous conditions should always be treated appropriately to prevent malignant change 

Factors leading to neoplasms:

* Viruses: causes some cancers in humans, ex: cervical carcinoma
* Gene and chromosomal abnormalities: mutations in gene that associate with tumor formation, ex: tumor-suppressor genes 

proto-oncogenes:

normal growth in the chromosomes that promote cell growth differentiation

oncogenes:

abnormally functioning gene that stimulate excessive cell growth

* unrestricted cell proliferation

tumor-suppressor genes:

* normally suppress cell proliferation
* loss of function by mutation may lead to unrestrained cell growth

DNA repair genes:

regulate processes that monitor and repair any errors in DNA duplication during cell division

failure of immunological defense play in the development of neoplasm:

cancers usually arise from the multiple genetic insults to the genome rather than single gene mutations

early warning signs/symptoms of neoplasms:

* Change in bowel or bladder habits 
* A sore that doesn’t heal 
* Unusually bleeding or discharge 
* Indigestion difficulty in swelling 
* Nagging cough 
* Unexplained weight loss

how tumors diagnosed:

* cytologic diagnosis
* frozen-section
* tumor associated antigen test

cytologic diagnosis:

* form smears of body fluids/ secretions
* fine needle aspirations

frozen-section:

* means of rapid evaluation of obtained tissue obtained at surgery
* permits immediate decision anbout proper course of treatment

tumor associated antigen test:

* some cancers secrete substances that can be detected by blood
* ex: CEA or PSA

tumor staging:

a system of categorizing malignant tumors in terms of their potential for invasion and metastasis

* TNM
* higher numbers associated with larger tumors or more extensive spread

T:

extent of tumor

N:

extent of the spread to lymph

M:

the presence of metastasis

tumor grading:

* Following a biopsy, various histological characteristics of the tumor are assessed and the tumor is assigned a grade 
* Based on degree of differentiation, frequency of mitosis

low grade tumor:

slow growing, limited tendencies to invade

high grade tumor

fast-growing tumor, aggressive tendencies to invade and metastasis

how tumors are treated:

* seeks to physically remove the tumor
* Drawbacks: edge of malignant tumor not well defined, If tumor has spread to lymph nodes, they must be removed, Surgery may produce emobili
* ex:
* radiation
* hormone
* chemo
* immuno

radiation therapy:

* Seeks to deliver a destructive dose of ionizing radiation to the tumor 
* May be used in conjunction with surgery 
* Useful for pain relief
* Drawbacks: can cause skin burns, also affect skin, hair ,GI mucosa, bone marrow 

hormone therapy:

* Some tumors require hormones for growth 
* Undergo temporary regression of deprived of require hormone

chemotheraphy:

* Toxic chemical substance are used to destroy tumor cells by interfering with metabolic pathways 
* Drawbacks: not able to select tumor cells, anemia, loss of appetite, nauseous, diarrhea, hair loss 

immunotherapy:

* Treatment of tumors by stimulating body immune system 
* Nonspecific: initially attempting by simulating generalized immune response 
* Specific: newer attempts try to stimulate specific cells of the immune system or act against tumor cells 

survival rates affecting neoplasm:

* Cancer is second to heart disease 
* ¼ people will eventually develop it 
* Early diagnosis and treatment may enhance survival 
* Chances for survival significantly reduced once tumor had metastasized raised to the regional lymph nodes 

5 year survival rates:

* refers to the percentage of patients who are alive 5 years after diagnosis
* Tumor may have already spread by time of diagnosis 
* recurrence: failure of body defenses reactivation of tumor