Flashcards in Session 9 - Neoplasia I Deck (58):
Define benign neoplasia
An abnormal growth of cells that persists after the initial stimulus is removed
Define malignant neoplasia
an abnormal growth of cells that persists after the initial stimulus is removed AND invades surrounding tissue with potential to spread to distant sites
Describe a benign neoplasia
Benign tumours grow in a confined local area and so have a pushing outer margin. Remains at site of origin.
Describe malignant neoplasia
Malignant tumours have an irregular outer margin and shape and may show areas of necrosis and ulceration. May spread to distant site forming new non-contiguous secondary growth (Metastasis).
What is a tumour?
A tumour is any clinically detectable lump or swelling
What is a cancer?
A malignant neoplasm
What is metastasis?
malignant neoplasm that has spread from its original site to a new non-contiguous site
What is the original location of a cancer called?
The original location is the primarysite and the place to which it has spread is a secondary site
What is dysplasia?
Dysplasia is a pre-neoplastic alteration in which cells show disordered tissue organisation. It is not neoplastic because the change is reversible.
Also indicated level of differentiation.
How differentiated are the cells of an
a) benign neoplasm
b) malignant neoplasm
a) Well differentiated
b) Well to poorly differentiated
What is anaplastic?
Cells with no resemblance to any tissue
What happens with worsening differentiation?
Individual cells have increasing nuclear size and nuclear to cytoplasmic ratior, more mitotic figures and increasing variation in size and shape.
What is Pleomorphism?
Variation in size and shape of cells and nuclei
What are a group of cells with no resemblance to any tissue called?
What does the term "grade" indicate?
The level of differentiation, highly graded being poorly differentiated
How is dysplasia used as a measure of altered differentiation?
Mild, Moderate and Severe dysplasi idicates worsening differentiation
What two things apparently cause neoplasia?
Initiators and promoters
For a neoplasm to develop, what must a mutation do?
The change must cause an alteration in cell growth and behaviour, and the change must be not lethal and passed onto daughter cells.
What are initiators?
What are promoters?
Things that cause cell proliferation
What genes can mutation occur in to cause neoplasia?
Proto-oncogenes OR Tumour Suppressor Genes
What happens if a mutation permanently activates a proto oncogene
it becomes an oncogene and neoplasia will occur
How does a tumour supressor gene cause neoplasia?
Must be permenantly inactivated
What are six key differences between neoplastic cells and normal cells?
Sandy Beache's Rectum Gets Invaded Regularly
- Self sufficient growth signals
HER2 gene amplification
- Resistance to anti-growth signals
CDKN2A gene deletion
- Grow indefinitely
Telomerase gene activation
- Induce new blood vessels
Activation of VEGF expression
- Resistance to apoptosis
BCL2 gene translocation
- Invade and produce metastases
Altered E-cadherin expression
Describe the clonality of neoplasms
Neoplasms are monoclonal. They are a cell population that are descended from a common ancestral cell
Describe a benign tumor
Variation in size and shape (Pleomorphism) minimal
Low mitotic count. Mitoses have normal form.
Retention of tissue specialisation
Desribe a malignant tumour
Variation in size and shape (Pleomorphism) minimal to marked
Low to high mitotic count. Mitoses may have abnormal forms.
Variable loss of tissue specialisation
(Well to poorly differentiated)
What is the differnece between in situa and malignancy?
All of the features of a malignant neoplasm in an epithelium, but no invasion through the basement membrane.
Name three initiators
Chemicals, infections, and radiation
Describe how neoplasms can be named
1.Benign or malignant
2.By tissue type
What do benign neoplasms end in?
What do malignant epithelial neoplams end in
What do malignant non epithelial neoplasms end in
What two states can a carcinoma be in?
In situ (no invasion of basement membrane) or invasive
What is a leukaemia?
a malignant neoplasm of blood-forming cells arising in the bone marrow
What is a lymphoma?
Malignant neoplasms of lymphocytes mainly affecting lymph nodes
What is a germ cell neoplasm?
Arise from pluripotent cells mainly in testis or ovary
What is a neuroendocrine tumour?
Arise from cells distributed throughout the body
What are blastomas?
Occur mainly in children and are formed from immature precursor cells
Give three places where benign epithelial neoplasms can occur
What is a stratified squamous neoplasm called?
Any tumour with finger-like projections
What is a transitional neoplasm called?
Transitional cell papilloma
What is a glandular neoplasm called?
Name four malignant carcinomas and where they may occur
Squamous Cell Carcinoma
Skin, larynx, oesophagus
Transitional Cell Carcinoma
Stomach, colon, lung, prostate, breast, pancreas
Basal Cell Carcinoma
What is a benign and malignant tumour of smooth muscle called
What is a benign and malignant tumour of Fibrous tissue
What is a benign and malignant tumour of bone
What is a benign and malignant tumour of cartilage
What is a benign and malignant tumour of fat called
What is a benign and malignant tumour of nerves called
What is a benign and malignant tumour of nerve sheath called
What is a benign and malignant tumour of glial cells
What is a myeloma?
Malignant plasma cell neoplasm in bone marrow, destroying adjacent bone
Why are all lymphomas considered malignant?
Already in blood
Describe lymphomas, and give two leukaemia names
Occurxs in lymphoid tissue
Usually lymph nodes
Hodgkins Disease and Non Hodgkins lymphoma
What is a haematopoietic tumour?
Acute and Chronic Leukaemia
Occurs in bone marrow
Abnormal cells then enter the blood
Name two germ cell neoplasms of the testis