Repro 2 Flashcards
Anatomically, what is the cervix divided into?
Exocervix – lined by nonkeratinizing epithelium
Endocervix – lined by a single layer of columnar cells
What is the junction between the exocervix and endocervix called?
The transformation zone
What type of genetic material is found in HPV?
HPV is a DNA virus
Where does HPV typically infect?
The lower genital tract (vulva, vaginal canal, cervix), particularly the cervix in the transformation zone.
HPV is divided into high risk and low risk strains. What is this distinction based upon? What does the risk refer to?
DNA sequencing. High risk types are HPV strains associated with a greater risk of developing cervical carcinoma.
What are the 4 common high risk type of HPV?
16, 18, 31, 33
What are the two common low-risk types of HPV?
6, 11
What is the pathogenesis of the high-risk types of HPV?
High risk HPV produce E6 and E7 proteins, which result in increased destruction of p53 and Rb, respectively. Loss of these tumor suppressor proteins increases the risk for cervical intraepithelial neoplasia (CIN)
How is cervical intraepithelial neoplasia (CIN) characterized histologically?
koilocytic change
disordered cellular maturation
nucelar atypia
hyperchromatic (dark) nuceli
increased mitotic activity
high nuclear to cytoplasmic ratio
within the cervical epithelium
Cervical Intraepithial Neoplasia (CIN) is divided into grades based upon what? What are the grades?
CIN is divided into grades based upon the extent of epithelial involvement by the dysplastic cells.
CIN I – involves <1/3 thickness of the epithelium
CIN II – involves <2/3 thickness of the epithelium
CIN III – involves slightly less than entire thickness
Carcinoma in situ – involves entire thickness of epithelium
What is cervical carcinoma?
cervical intraepithelial neoplasia that has progressed to become invasive carcinoma; CIN that has invaded the unerlying tissue
What is the most common demographic for cervical carcinoma?
middle-aged women (average age is 40-50 years)
How does cervical carcinoma present?
vaginal bleeding, especially post-coital bleeding
or cervical discharge
What is the key risk factor for cervical carcinoma?
Infection with high-risk HPV (16, 18, 31, 33)
What are the secondary risk factors for cervical carcinoma?
smoking
immunodeficiency (cervical carcinoma is an AIDS-defining illness)
What are the two most common subtypes of cervical carcinoma?
squamous cell carcinoma (80%)
adenocarcinoma (15%)
Both types are related to HPV infection.
What is the characteristc way cervical carcinoma spreads? What is a common cause of death in advanced cervical carcinoma?
Cervical carcinoma tends to invade locally through the anterior uterine wall into the bladder, blocking the ureters.
Hydronephrosis with post-renal failure is a common cause of death in advanced cervical carcinoma.
What is the gold standard for cervical cancer screening?
Pap smear
What are some limitations of the Pap smear?
- inadequate sampling of the transformation zone (false negative)
- limited efficacy in screening for adeenocarcinoma
(despite pap smear screening, the incidence of adenocarcinoma has not decreased significantly)
What subtypes of HPV does the vaccine cover?
The vaccine is a quadrivalent vaccine that covers types 6,11, 16, and 18
What do the antibodies generated against HPV subtypes 6 and 11 protect against?
chondylomas
What do the antibodies generated against HPV subtypes 16 and 18 protect against?
Cervical intraepithelial neoplasia (CIN) and carcinoma
How long does the protection last with the HPV vaccine?
5 years
Does a woman vaccinated against HPV need to get pap smears? Why?
Yes!
Pap smears are necessary due to the limited number of HPV types covered by the vaccine.