Pathology Tumor Flashcards
Normal cell growth requires
Genetic material, aka DNA and RNA
Signals from one cell to another
Growth inhibiting or growth promoting substances
Once a cell stops growing it needs to differentiate - to become specialized - by activating some genes, and suppressing other genes
Tumour cells do not achieve the same level of differentiation as normal cells
Neoplasia
Neoplasm - new growth
Uncontrolled cell growth whose proliferation can not be adequately controlled by normal regulatory mechanisms
Neoplastic cell proliferation is:
Autonomous - independent of normal growth factors and inhibitors
Excessive - doesn’t respond to normal regulators
Disorganized - compared to the formation of normal tissues
Classification of tumour
Benign - limited growth potential and good outcome
Malignant - grow uncontrollably with poor outcome
Histologic classification
Based on how cells look under the microscope
Benign Tumours Microscopic Features
Sharply demarcated
Often encapsulated (CT tissue)
Can have expansive growth which compresses adjacent tissue leading to atrophy and fibrosis
Can be easily removed by surgery
No hemorrhage or necrosis
Resemble the original tissue from which they have arisen
Show high level of differentiation (it might show nucleus, mitochondria)
Benign tumours cellular features
Uniform cell populations (homogenous)
Regularly shaped/same sized nuclei
Well developed cytoplasm (sign that specialized)
Nucleus occupies a small portion of the cell
Nucleus has even distribution of chromatin
Nucleoli are not overprominent
Benign tumors chromosomal features
has normal number of chromosomes
Benign Tumor biological features
Retain normal complex functions
Malignant tumors macroscopic
no clear margins from normal tissue No encapsulation can have INVASIVE growth can not be removed easily by surgery Hemorrhage and necrosis present
Malignant Tumours microscopic
Differ considerably from original tissues
Show anaplasia (cells take on new characteristics)
Undifferentiated
Still can tell where the tissue originally came from (ex. breast tissue in the liver)
What is anaplasia
cells take on new characteristics
Malignant Tumors cellular features
Don’t have uniform cell populations (heterogenous)
Cells vary in size and shape
Nuclei vary in shape and size
Variable amounts of cytoplasm
Nucleus is larger
Hyperchromatic (more chromatin, unevenly distributed, nucleoli prominent, multiple)
Malignant tumours chromosome features
Aneuploid (abnormal number of chromosomes)
Malignant tumours Biological features
No specialization or differentiation
Metabolism is geared toward supporting growth and replication
what is Metastases
A proces by which cells move from one site to another in the body
What is pleomorphism
nucleus or cells in various sizes and shapes
Metastasis of Malignant tumor 3 pathways
Involves a spread of tumor cells from a primary location to another site in the body spread can occur through 3 main pathways 1. Lymphatics 2. Blood (hematogenous spread) 3. Body cavities
Metastastic cascade
Not all malignant cells are capable of metastasis
Cells must acquire the capacity to metastasize
Cells then expand clonally
clone expands, cells reach lymphatics or blood vessels or body cavity
Fluid carries the cells from the primary site to distant locations where cells attach and begin forming a new tumour mass
Metastatic cells must escape immune cells including macrophages, T cells, NK cells
Malignant tumour must form new blood vessels (angiogenesis)
Benign tumours of mesenchymal cells
end in “-oma”
Benign tumor from fibroblast
Fibroma
Benign tumor from Cartilage
Chondroma
Benign tumor From adipose
Lipoma
Benign tumor From smooth muscles cells
Leiomyoma
Benign tumor From bone
Osteoma
Benign tumors of striated muscle cells
Rhabdomyoma
Benign tumors of Epithelial cells
Adenoma -composed of glands or ducts
Benign tumors of Epithelial cells in the GI tract
Tubular or villous adenomas (aka polyps)
