MOD S9 - Neoplasia I Flashcards
What is the difference between benign and malignant neoplasms?
Malignant ones invade and spread to other sites (metastasise) whereas benign remain at the site of origin
Malignant have irregular edges due to infiltrative growth edges but benign have smooth, rounded edges (minimal variation in size and shape)
Malignant have a higher mitotic count and may have abnormal forms
Benign tend to retain their specialisation but malignant can be poorly differentiated
Define neoplasia
The abnormal growth of cells which persists after the initiating stimulus has been removed
What factors are necessary for a mutation to lead to a neoplasm?
The mutation must:
Cause an alteration in cell growth and behaviour
Be passed on to daughter cells
Not be lethal
Where can neoplasm-causing mutations take place?
Proto-oncogenes
Tumour suppressor genes
How will a mutation affect a proto oncogene to cause neoplasia?
If it is mutated so it is permanently activated, it becomes an oncogene
How will a mutation affect a tumour suppressor gene to cause neoplasia?
It is permanently inactivated
What are some key differences between neoplastic and healthy cells?
Self sufficient growth signals Resistance to anti-growth signals Grow indefinitely Induce new blood vessels Resistance to apoptosis Invade and produce metastases
How does a neoplastic cell have self-sufficient growth signals?
HER2 gene amplification
How does a neoplastic cell have resistance to anti-growth signals?
CDKN2A gene deletion
How does a neoplastic cell grow indefinitely?
Telomerase gene activation
How does a neoplastic cell induce new blood vessels?
Activation of VEGF expression
How does a neoplastic cell have resistance to apoptosis?
BCL2 gene translocation
How does a neoplastic cell invade and produce metastases?
Through altered E-cadherin expression
Discuss the clonality of neoplasms
They are monoclonal
Aka a cell population descended from one common ancestor (which mutated to escape normal growth control)
Define dysplasia
Abnormal maturation of cells within a tissue
How can a carcinoma in-situ be distinguished from a malignancy in epithelial tissue?
They share all the features of a neoplasm, but a carcinoma will not have invaded the tissue beneath the basement membrane
How are neoplasms named?
If they are benign or malignant
By tissue type (epithelial, connective, haemopoietic, ect)
What would a benign neoplasm in a stratified squamous epithelium be called?
A squamous papilloma
What would a benign neoplasm in a transitional epithelium be called?
Transitional cell papilloma
What would a benign neoplasm in a glandular epithelium be called?
An adenoma
What would a malignant epithelial neoplasm be called?
A carcinoma
Where could a squamous cell carcinoma be found?
Skin, larynx, oesophagus
Where could a transitional cell carcinoma be found?
Bladder, ureter
Where could an adenocarcenoma be found?
Stomach, colon, lung, prostate, breast, pancreas
Where could a basal cell carcinoma be found?
Skin
What would be the benign and malignant names for a smooth muscle neoplasm?
Benign: leiomyoma
Malignant: leiosarcoma
What would be the benign and malignant names for a fibrous tissue neoplasm?
Benign: fibroma
Malignant: fibrosarcoma
What would be the benign and malignant names for a bone neoplasm?
Benign: osteoma
Malignant: osteosarcoma
What would be the benign and malignant names for a cartilage neoplasm?
Benign: chondroma
Malignant: chondrosarcoma
What would be the benign and malignant names for a neoplasm in fat tissue?
Benign: lipoma
Malignant: liposarcoma
What would be the benign and malignant names for a neoplasm in nerves?
Benign: neurofibroma
Malignant: neurofibrosarcoma
What would be the benign and malignant names for a neoplasm in a nerve sheath?
Benign: neurilemmoma
Malignant: neurilemmosarcoma
What would be the benign and malignant names for a glial cell neoplasm?
Benign: glioma
Malignant: malignant glioma
Why are there no benign haemopoietic or lymphoid neoplasms?
They are all regarded as malignant because they are already all over the body as they are in the blood
What would a lymphoid neoplasm be called?
Lymphoma (B and T)
Describe lymphomas
Neoplasia of lymphoid cells
Usually in lymph nodes
Can be further categorised as Hodgkin’s disease or non-Hodgkin’s lymphoma
What would a haemopoietic neoplasm be called?
Acute or chronic leukaemia
Describe a myeloma
Malignant plasma cell neoplasm
Found in bone marrow
Destroys adjacent bone
What neoplasms can occur in the testis?
Malignant teratoma
Benign seminoma
What neoplasm could occur in the ovary?
Benign teratoma or dermoid cyst
