Diseases of the female genital system 1 Flashcards
What is meant by VIN?
Vulval intraepithelial neoplasia
What is meant by CIN?
Cervical intraepithelial neoplasia
Intraepithelial neoplasia refer to what kind of growth?
Dysplasia
What is meant by CGIN?
Cervical glandular intraepithelial neoplasia
What is meant by VaIN?
Vaginal intraepithelial neoplasia
What is meant by AIN?
Anal intraepithelial neoplasia
Intraepithelial neoplasia of the female genital system can be caused by which virus?
HPV virus
What is dysplasia?
Earliest morphological manifestation of multistage process of neoplasia, its in situ disease (ie. non-invasive), shows the cytological features of malignancy without invasion
Is dysplasia treatable?
Yes as it is not invasive
Does HPV infection always cause harm?
No, in most women HPV will not cause long term harm and will be cleared by the immune system
The lifecycle of HPV is linked to what?
Epithelial differentiation
How many subtypes of HPV are there?
> 100, based on DNA sequence - different types infect different tissues
Genital HPVs are grouped into what 2 categories?
1) Low risk
2) High oncogenic risk
Low risk HPVs are associated with what?
Lower genital tract warts (condylomas = benign squamous neoplasms) and low grade intraepithelial neoplasms
High risk HPVs are associated with what?
Hihg grade intraepithelial neoplasma and invasive carcinomas
Which are the 2 most common low risk HPVs?
6 and 11
Which are the 2 most common high risk HPVs?
16 and 18
What percentage of cervical cancers contain HPV?
99.7% (types 16 and 18 associated with 70% of all cervical cancers)
Why is all cervical cancer not prevented by HPV vaccine?
Current HPV vaccine only vaccinates against the 2 low risk types (6 and 11) and the 2 most common high risk types (16 and 18) - other types can cause cervical cancer
What 2 types of genes are possessed by HPVs and what is the role of each?
Early genes - expressed at onset of infection, control viral replication and in oncogenic viruses are involved in cell transformation
Late genes - encode capsid proteins
High risk HPVs intergrate into the host chromosomes, which 2 proteins does it upregulate the expression of?
E6 and E7
What does the protein E6 do in cells infected by high risk HPV, what effect does this have?
Binds to and inactivates P53
P53 normally mediated apoptosis in response to DNA damage so as a result of its inactivation get accumulation of genetic damage
What does the protein E7 do in cells infected by high risk HPV, what effect does this have?
Binds to an inactivates RB1 which is a tumour suppressor gene which controls G1/S checkpoint in cell cycle thus through its inactivation you have dysregulation of cell proliferation
What are the 2 molecular pathways for the development of VIN?
1) Classical/ warty/ baseloid
2) Differentiated VIN
The classical/ warty/ baseloid VIN is related to what and most common in which group?
Most common in younger people
Related to HPV infection
Is the classical VIN graded?
Yes Graded 1-3
The differentiated VIN is related to what and occurs in which group?
Occurs in older people
NOT related to HPV - occurs in chronic dermatoses (inflammatory skin conditions) especially Lichen Sclerosus
Is differentiated VIN graded?
No
What percentage of cases of VIN recur and what is a predictor of recurrence?
35-50% recur Positive margins (ie. neoplastic cells extend beyond the edge of the tissue resected) predicts recurrence
What is the difference in rates of progression to invasive Ca in untreated and treated VIN?
Treated VIN (surgery) - 4-7% Untreated VIN - 87%