Gen Path Exam 3 Section 5: Neoplasia Flashcards
Top three estimated cancer incidences in males and females
Males:
- Prostate
- Lung and Bronchi
- Colon and Rectum
Females:
- Breast
- Lung and Bronchi
- Colon and Rectum
Top three estimated cancer deaths in males and females
Males:
- Lung and Bronchus
- Prostate
- Colon and Rectum
Females
- Lung and Bronchus
- Breast
- Colon and Rectum
Neoplasm
= “new growth”; refers to tissue masses called tumors; all have dysregulated growth; can be benign or malignant, which will determine prognosis
Benign Tumors
= neoplasms that have “relatively innocent” cellular characteristics
- localized to single area; will NOT metastasize
- most cause no harm; but some can b/c they do take up space
- most likely to be excised due to lack of invasivness
- slow growing, encapsulated or surrounded by CT, fairly mobile when palpated
What determines the dysfunction caused by Benign Tumor’s pressure?
- which tissues being compressed
2. how much compression is occurring
Naming of a benign tumor
tissue type involved, plus the suffix “-oma”
Ex: Hemangioma
Exception: melanocytic Nevus
- Fibrotic tissue
- Fat tissue
- Cartilaginous tissue
- Glandular Tissue
What are the benign tumor names?
- fibroma
- lipoma
- chondroma
- adenoma
Hemangioma
benign tumor of capillary endothelia
Leiomyoma
benign smooth muscle tissue tumor, AKA “uterine fibroid”
Fibroadenoma
MC benign tumor of breast; benign; multiple tissues, “mixed” tumor, contain fibrotic component and a glandular component
Polyp
mass of tissue that projects above a mucosal surface; a gross structure; and must be biopsied to know cellular nature
Ex: colon polyp
Papilloma
a benign epithelia neoplasm that produces microscopic “finger-like fronds”; very small extensions/outgrowths away from the surface
- macroscopically = a wart (verruca)
- stimulated by HPV infections
Hamartoma
mass of overgrowing tissues that are native to site/tissues of the area; very similar to normal cells (therefore usually always benign)
Ex: pulmonary hamartoma
What two things are all tumors composed of?
- parenchyma
2. stroma
Parnechyma
the genetically altered component of a tumor; determines biological nature (aggressiveness) of tumor; also determines name given to tumor
Stroma
composed of tissues that support and surround parenchyma mass; provides blood supply and supportive structures to tumor
Mixed tumors
when tumor performs “divergent differentiation” and multiple tissue types are found within a tumor
- more likely to be benign and less aggressive
Differentiation
degree to which tumor cells resemble their cell of origin
- well-differentiated tumors = very similar to progenitor cells
- poorly differentiated tumors = do NOT resemble their progenitor cells
Anaplasia
a lack of differentiation in neoplastic cells; cells that lack specialization; more “immature” and DO NOT contain cellular features expected in more “mature”/differentiated cells
Pleomorphic Adenoma
of salivary galnds; benign mixed tumor, contain glandular tissue, osseous tissue, and cartilaginous tissue
Teratomas
mixed tumor; involves at least two of the three embryonic germ layers; frequently all three
- Commonly involves: bone, cartilage, epithelia, muscle, fat, hair, teeth, or nerves
- may be benign OR malignant
Malignant tumors (malignancies)
= cancers; sarcomas and carcinomas
Naming: prefix = tissue type and “carcinoma” or “sarcoma” is the suffix
Sarcomas
malignant neoplasms that originate from solid mesenchymal (CT)
What are cancers that arise from mesenchymal cells in the blood?
- leukemia - WBC cancer in circulating blood or in bone marrow
- lymphoma - WBC cancer in lymphatic system
What type of individuals do sarcomas usually affect?
young (pediatric) and those in adulthood and older adulthood (geriatrics)
What are the MC pediatric tumors?
leukemia and bone cancer (osteosarcoma)
Carcinomas
cancers that originate from epithelial cells (from endoderm or ectoderm)
- MC form of cancer in humans
- develop in a pattern: dysplasia –> carcinoma in situ –> invasive carcinoma
What type of individuals are affected by carcinomas?
more likely age-related cancers; very unlikely in first 1/2 of life
What are adenocarcinomas and squamous cell carcinomas examples of?
carcinomas
adenocarcinoma = develop in glandular pattern
squamous cell carcinomas = develop in squamous pattern
Dysplasia
disorderly proliferation of cells and is risk for further cellular irregularities
Carcinoma In Situ
earliest form of cancer; referred to as “pre-invasive” cancer
- Stage 0 b/c yet to penetrate tissues
- lies at division b/w pre-neoplastic (pre-cancerous) lesions and invasive carcinomas
What is Ductal Carcinoma In Situ an example of?
a carcinoma in situ
- a very common form of “Stage 0” breast cancer; frequently discovered upon mammography
What are the four main characteristics talked about for tumors?
- if benign or malignant
- Rate of Growth
- Local Invasion
- Metastasis
Benign vs malignant tumors and cell types
benign tumors = more likely to have cells with greater degrees of differentiation
malignant = more likely to contain anaplasia
Rate of Growth and association with Benign and Malignant tumors
in general:
- malignant tumors have more rapid growth
- BUT slow growing cancers are fairly common (Ex: prostate cancer, Hodgkin Lymphoma)
- AND some benign tumors may grow rapidly (Ex: giant cell tumor of bone with distal radius)
Local Invasion and association with tumors
= infiltration or local destruction
- represents a tumor invading surrounding tissues as it grows
- Benign tumors – tend to grow slowly and be encapsulated
- NOT all benign tumors are encapsulated
- rare cases some malignant tumors are encapsulated and some benign tumors are uncapsulated (Ex: hemangioma)
Metastasis and association with tumors
= “mets” for short; the spread of tumor to distant sites within body that are no longer continuous with primary tumor
*characteristic of malignant tumors (no benign tumor performs mets)
~30% all tumors are diagnosed at point where have metastasized
Where may a tumor invade (metastasis)?
tissue cavities, lymphatics, or hematopoietic (blood) system
- in general, larger the tumor and more anaplastic cells = more likely to metastasize
Why are blood cell cancers a special exception to metastasis?
leukemias and lymphomas are already throughout blood stream and lymphatic system, therefore virtually all are metastatic and time of diagnosis
What are the 3 routs of Metastasis?
- Seeding within Body Cavities
- Lymphatic Spread
- Hematopoietic Spread
Seeding within Body Cavities (metastasis)
(transcoelomic spread)
- rare compared to other types
- characteristic of ovarian cancers and cancers of CNS that spread within preexisting cavities where located
Lymphatic Spread (metastasis)
- characteristic of metastasis for carcinomas
- location of primary cancer and proximity to local lymphatics
- “sentinel lymph node”
Sentinel Lymph node
first lymph node that receives lymphatic drainage from area where primary tumor located
- enlargemnt of this node = lymphadenopathy
Hematopoietic Spread (metastasis)
- characteristic spread for sarcomas (CT)
- frequently spread to 1st capillary bed encountered
Ex: - colorectal and GI cancers —> liver
- bone cancer/other organ system cancers –> lungs
- vert. mets = common site for cancer to mets to
Epidemiology
the study of death and disease in groups of people (populations)
- provides info on pathogenesis of tumors and info on risk factors ass. with diff cancers
What are the common cancers in these geographic locations?
- US
- Africa
- Japan
- breast, colorectal, and esophageal cancer
- liver cancer
- stomach cancer
What ages have the highest rates of cancer related deaths?
ages 55-75
Due to:
- somatic mutations with exposure to env. carcinogens
- less active immune system
- cell activities less active and efficient
Is cancer diagnosis increasing or decreasing?
Are cancer rates stable or not stable?
Are rates of cancer related deaths in US increasing or decreasing?
- cancer diagnosis is increasing, mainly due to increasing population
- cancer rates are stable
- rates of cancer-related deaths in US is decreasing (~20% reduction for men; ~10% reduction for women)
What are sporadic cancers?
develop with NO family history of cancer; due to harmful env. exposure and damage to individuals genetic material
What are common characteristics for preneoplastic lesions?
cellular metaplasia and dysplasia
Where do most tumors/ preneoplastic lesions develop?
at sites of chronic inflammation
What do sites for preneoplastic changes tell us about risk of cancer?
increase risk of cancer, BUT in most cases cancer does NOT develop
- most benign tumors = NOT precancerous lesions
- —-Exception: adenoma in lumen of colon –> they have a high rate of malignant transformation and ARE preneoplastic lesions
What are Cancer Genes?
= cancer developing following genetic alterations
What are germ line mutations?
gene mutations that are inherited
What three things can alter genes that regulate cellular growth?
- carcinogenic chemicals
- ionizing radiation
- viral infections
What are proto-oncogenes?
normal genes that promote cellular growth; can be altered/ mutated into cancer-promoting “oncogenes”
What are oncogenes?
when an proto-oncogene is altered
- only need a single allele to alter proto-oncogene = Dominant Change of Gene Expression
What are Tumor Suppressor Genes?
(TSGs)
= normal genes that slow down cellular growth
- if altered they lose ability to slow down growth
- BOTH TSGs alleles need to be altered = Recessive Change of Gene Expression