Neoplasia 1 Lecture Flashcards
Define neoplasia
New growth
- Tumor is an abnormal mass of tissue, the growth of which is virtually autonomus and exceeds that of normal tissues –> persists after cessation of the stimuli that initiated its change
All tumors have two components?
Parenchyma (proliferating neoplastic cells) Supporting stroma (connective tissue and blood vessels
Benign tumors?
End with “oma”
- has the same characteristics as its’ parent
Adenomas
Benign epithelial tumors arising in glands or forming grandular patterns
Cystadenomas
Adenomas producing large cystic masses, typically in ovaries
Papillomas
Epithelial tumors forming microscopic or macroscopic finger-like projections
Polyp
A tumor projecting from the mucosa into the lumen of a hollow viscus
- Macroscopically visible projections above a mucosal surface
Malignant Tumors
Cancerous tumors
- Mesenchymal tissues - sarcomas (fleshy because of little stroma) or epithelial- carcinomas
Malgnant tumors classification
With glandular growth patterns - adenocarcinoma
- Recognizable characteristics of cells found than so named - squamous cell carcinoma
- Not recognizable- poorly differentiated or undifferentiated - carcinoma
- Sometimes mixed tumors (tumor of salivary gland origin
Characteristics of neoplasms
Distinction between benign and malignant tumors is based on the appearance (morphology) and ultimately on behavior (clinical course)
Define differentitation
Extent to which tumor cells resemble comparable normal cells
- Benign tumors are well differentiated (look like a normal cell)
- Malignant neoplasms are in general less well differentiated than benign
Anaplashia
Lack of differentiation (hallmark of malignant cells)
Features of Anaplasia
Nuclear and cellular pleomorphism Hyperchromatism Nuclear-cytoplasmic ratio Abundant mitoses Tumor giant cells Loss of polarity
Nuclear and cellular pleomorphism
Wide variation in the shape and size of cells and nucleus
Hyperchromatism
Darkly stained nuclei that frequently contain prominent nucleoli
- Much larger than normal cells
Nuclear-cytoplasmic ratio
1:1 instead of 1:4 or 1:6, reflecting enlargement of nuclei
Abundant mitoses
Reflect proliferative activity, mitotic figures may be abnormal
- All different versions of mitosis
Tumor giant cells
Contain a single large polyploid nucleus or multiple nuclei
Loss of polarity
Poorly differentiated, anaplastic tumors also demonstrate a total disarray of tissue architecture
- Lost differentiation
Define dysplasia
Disorderly but non-neoplastic growth (mild degrees of dysplasia, but do now always leading to cancer and are often reversible when the inciting cause is removed
- Usually in the epithelial, involve the entire thickness (can be considered a preinvasive neoplasm –> carcinoma in situ)
- Forerunner in may cases of invasive carcinoma
Rate of growth
Malignant tumors grow more rapidly than benign tumors
- Some cancers grow slowly for years and then enter a phase of rapid growth
- Growth of cancers arising from hormone sensitive tissues… May be affected by variations in hormone levels associated with pregnancy and menopause
Rapidly growing malignant tumors often contain
Central areas of ischemic necrosis because the tumor blood supply falls to keep pace with the oxygen need of the expanding mass of cells
Local invasion of benign tumors
Grow as cohesive expansile masses that develop a rim of condensed connective tissue or capsule at the periphery (do not invade, they are encapsulated)
- Surgical enucleation: plane of cleavage between the capsule and the surrounding tissues
Local invasion of malignant tumors
Invasive, infiltrating, and destroying normal tissue surrounding them
- Lack a well-defined capsule and plane of cleaving, making enucleation difficult or impossible
- Surgical treatment of such tumors requires removal of a considerable margin of healthy uninvolved tissue
Metastasis
Involves invasion of the lymphatics, blood vessels, and body cavities by the tumor, followed by transport and growth of secondary tumor cell masses that are discontinuous with the primary tumor
Exception to metastasis
Tumors in the brain and basal cell carcinomas of the skin, almost all other malignant tumors have the capacity to metastasize
Routes of metastasis
Spread into body cavities
Invasion of lymphatics
Hematogenous spread
Spread into body cavities
By seeding of surface of any cavity
Invasion of lymphatics
Transport of tumor cells to reginal nodes and other parts of the body –> common in the initial spread of carcinomas
Hematogenous spread
Using the blood system, starting in the kidneys
- Tumor uses the veins to get into the system
- Common in lungs and liver
Benign tumors differentiation, rate of growth, local invasion, metastasis
Well-differentiated
Usually slow, may stop growing or regress; mitotic figure are rare and normal
Usually cohesive and well-demarcated masses that do not invade or infiltrate surrounding normal tissues
Absent metastasis
Malignant tumors differentiation, rate of growth, local invasion, metastasis
Range of differentiation with anaplasia; atypical structure
Erratic, mitotic figures numerous, abnormal
Locally invasive, infiltrating the surrounding normal tissues
Frequently present, more poor differentiation- greater the chance of metastasis
Male and female cancers that are most prominent? Highest death rate?
Prostate and breast cancer
Lung
Age and cancer?
55+ yo or >15 yo
- Tumors of hematopoietic systems, neuroblastomas, wilms tumors, retinoblastomas, sarcomas of bone and skeletal muscles
Heredity and cancer
Inherited cancer syndromes
Familial cancer
Autosomal recessive syndromes of defective DNA repair
Inherited cancer syndromes
Characterized by inheritance of single mutant genes (cancer suppressor) that greatly increases the risk of developing a certain type of tumor
- Regulate cell growth
Familial Cancers
Characterized by familial clustering of specific forms of cancer, but the transmission pattern is not clear in an individual case (breast, colon, brain, etc)
Autosomal recessive syndromes of defective DNA repair
Characterized by chromosome or DNA instability that greatly increases the predisposition to environmental carcinogens
Acquired Preneoplastic Disorders Precancerous Conditions
Certain clinical conditions are associated with an increased risk of devloping cancers
Cirrhosis of the liver
Hepatocellular carcinoma
Atrophic gastrisits of pernicious anemia
Stomach cancer
Chronic ulcerative colitis
Carcinoma of the colon
Leukoplakia of the oral and genital mucosa
Squamous cell cancers
Solar keratosis of the skin
Skin cancers
