An introduction to neoplasia Flashcards
What is the clonal evolution model
- this is the idea that tumours are from clones
- but as they grow they gain more mutations
- they have different shapes, size and molecular biology
- each new mutation adds a new characteristic
- autonomous or normal growth signals
those with a growth advantage are dominant
what is the cancer stem cell hypothesis
- idea that a normal stem cell leads to mutated stem cells which lead to cancer stem cells
- normal progenitor cell leads to a mutated progenitor cell which leads to cancer stem cell
- normal differentiated cell leads to a muted differentiated cell which leads to a cancer stem cell
what is a property of cancer stem cells
they are self renewal
what is a neoplasm
A neoplasm is an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues, and persists in the same excessive manner after cessation of the stimulus which evoked the change.”
what are the various types of growth
- Benign
- precancerous
- carcinoma in situ
- malignant (cancerous tumours)
what does the initial development and growth depend on
- depends on a population of a single type of neoplastic or transformed cells that are derived from a progenitor cell, these cells are identical and are clonal cells
neoplasms often contain …
more than one cell type
what is hyperplasia and what does it result in
this is an increase in overall muscle mass due to corresponding increase in the size of cells
- leads to benign tumour forming
what is dysplasia what does it lead to
- this is an increase in the number of cells present, abnormality in growth and maturation of cells within tissues
- often an indication of an early neoplastic process
- pre-cancerous
what is carcinoma in situ
- this is when the cells become primitive in capability
- invasive potential, may result in the formation of a malignant tumour
what is invasive cancer
this is when cells have the ability to invade nd metastasis
what are the stages of tumour development
- hyperplasia
- dysplasia
- carcinoma in situ
- invasive cancer
what is hyper plastic cells
these are a excessive number of cells that can assemble into tissue which appears reasonably normal
what are examples of hyper plastic cells
Examples:
Benign prostatic hyperplasia (BPH)
Atypical lobular hyperplasia (breast)
Atypical ductal hyperplasia (breast
what is metaplasia
this is when a normal layer is replicated by a cell type that is not normally found in that location
- invading cells are microscopically normal
- often occurs in epithelial transition zones (e.g. junction of cervix and uterus and oesophagus and stomach)
what is an example of metaplasic tumours
Example: Barrett’s oesophagus
(30x increased risk developing
oesophageal adenocarcinomas).
describe dysplasia
abnormal growth
- some but not all of the features in malignancy are present
- transitional state between benign and pre=malignant
- dysplasia may develop into malignancy
what are example of dysplasia cacners
Colonic polyps
Uterine cervix
how do you grade dysplasia
- depends on the thickness of the involved epithelium
what is the grading system of the epitheium
-Cervix - normal stratified squamous epithelium
- CIN I - disease confined to the lower third of the epithelium - this is mild
CIN II - diseased confined to the lower and middle thirds of the epithelium - moderate
CIN III - affecting the full thickness of the epidermis this is severe
what are the grade dysplasia in bronchial epithelium
(A) Normal two-layered epithelium; (B) squamous metaplasia; (C) mild dysplasia; (D) moderate dysplasia; (E) severe dysplasia; (F) carcinomain situ.
what are the characteristics in dysplasia
- Variability nuclear size and shape - > nuclear: cytoplasmic ratio - Increased mitotic activity - Change in the relative numbers of specific cell types
these are major changes in the cytoarchitecture
what is the epithelia layer derived from
- all three germ layers in the embryo, these are the ectoderm, mesoderm, and endoderm
What makes up the ectoderm
Skin epidermis
Glandular tissue of breast
what makes up the mesoderm
ovaries
what makes up the endoderm
Lungs Liver Gall bladder Pancreas Stomach Intestine
what is epithelia called in term of tumours
- carcinoma
what do lining and covering epithelia cover
Forms the surface of the skin and some internal organs. It forms the inner lining of ducts and body cavities and the interior of the respiratory, digestive, urinary and reproductive systems – stratified squamous
what does the glandular epithelium cover
Are found in organs such as the thyroid, adrenal glands and sweat glands. And glands in breast and prostate. Specialised polarised cells which secrete into ducts or cavities –simple cuboidal and simple columnar.
what are most human cancers
they are epithelial in origin and are carcinomas
what are two common types of epithelial cancers
- Producing recognizable squamous cells: squamous cell carcinoma (nasal cavity, larynx, lung, cervix, skin).
- Glandular growth pattern: adenocarcinoma (lung, colon, breast, pancreas, stomach prostate).
what is the difference between normal prostate glands and malignant prostate glands in prostate adenocarcinoma
Normal Columnar and some cuboidal luminal cells Pale cytoplasm Inconspicuous nucleoli Basal cells Flattened/cuboidal
Malignant note size of nucleus: cytoplasm and prominent nucleoli absence of basal cell layer hyperchromasia
what is abnormal nuclear morphology
Hyperchromasia
Chromatin clumping
Prominent nucleoli
Little cytoplasm
Increased nuclear: cytoplasmic ratio
(>1:5 to 1:1)
Frequent mitosis (yellow arrows)what happens in abnormal mitosis
- proliferative activity is high (mitotic rate is high)
- increased number of mitotic figures
what are the different spindles
- tripolar
- quardripolar
- multipolar spindles
what is pleomorphism
variation in cell shape and size often larger than normal
what are the different types of pleomorphism
Cellular pleomorphism
Nuclear pleomorphism
Hyperchromatic nuclei
Tumour giant cells
what are the features of anaplasia
pleomorphism
abnormal nuclear
morphology
mitoses (abnormal
Loss of polarity
Normal cells are anchored and oriented to the basement membrane
Anaplastic cells lose this orientation and grow in a disorganised way
Other things
Tumour giant cells
Ischemic necrosis (as tumour outgrows its blood supply)
where are sarcomas derived from
mesodermal tissues
what are the two main types of sacromas
bone
soft tissue
describe the sarcomas in the soft tissue
Muscle (skeletal and smooth) Cartilage Fat Nerves Fibrous tissue, such as ligaments and connect tissue Blood vessels Lymph vessels
what are the types o f blood cancers
- leukaemia
- lymphoma
- multiple myeloma
where are blood cancers derived from
haematopoietic and lymphoid tissues
what is leukaemia and which cells does it affect
– malignancies of the bone marrow (abnormal white blood cells) Lymphoid Myeloid Acute Chronic
what is lymphoma and what are the type types
malignancies of the lymphoproliferative system
Hodgkin- lymph nodes, the spleen and liver
Non-Hodgkin - lymph nodes and extra-nodal including the gastrointestinal tract, skin and bone
what is multiple myeloma and where does it effect
neoplastic proliferation of B cells in bone marrow - plasma cells producing a characteristic paraprotein (abnormal antibody).
