HPV Flashcards
High risk strains of HPV?
HPV 16 and 18
Low risk strains of HPV?
HPV 6 and 11
HPV incubation period?
3 weeks to 9 months
-still contagious during this time and so likely to acquire from an asymptomatic partner
what strain of HPV typically causes genital warts and cervical cancer?
genital warts= low risk HPV= HPV 6 and 11
cervical cancer= high risk HPV= HPV 16 and 18
What types of cancer does HPV commonly cause?
-Cervical (HPV is the most common cause)
-Oropharynx
-Anus
-Penis
-Vulva
-Vaginal
How does HPV promote cancer?
-by inhibiting tumour suppressor genes p54 and pRb
What vaccine is given for HPV and what strains does it cover?
2 doses of the Quadrivalent vaccine
-covers HPV 6, 11, 16 and 18
who is given the HPV vaccine?
MSM <45
Girls and boys 12- 13
how often are women with HIV screened for cervical cancer?
yearly
Histology of genital warts?
Thickened papillomatous squmous epithelium with cytoplasmic vacuolation (Koilocytes)
KOYLOCYTE- type of epithelial cell that develops following a HPV infection
Treatment for genital warts
-Topical Podophylotoxin
-Imiquimod (can take 3/4 months)
-Cryotherapy
Surgical:
-Electrocautery
complications of genital warts?
-can progress to intra epithelial neoplasia
what are some precancerous changes in the cervix?
-Cervical intraepithelial neoplasia
-Cervical glandular intraepithelial neoplasia (CGN)
what is cervical intraepithelial neoplasia?
-a pre invasive stage of cervical cancer
-dysplasia of squamous cells at the transformation zone in the cervix
genital warts can go on to form cervical intraepithelial neoplasia
what cells is the ectocervix lined by?
non keratinised stratified squamous epithelium
what cells is the endocervix lined by?
mucous secreting glandular cells
-simple columnar epithelium
what is the transformation zone of the cervix?
-area in the cervix where the endo/ ecto cervix meet
-there is an abrupt change from glandular/ columnar cells from the endocerxix to the non keratinised stratified squamous epithelium in the ectocervix
-this is where cancer is most likely to occur
-also where cervical smears are taken
what is cervical glandular intraepithelial neoplasia?
-pre invasive form of endocervical adenocarcinoma
is it easier to screen for cervical glandular intraepithelial neoplasia or cervical intraepithelial neoplasia?
easier to screen for cervical intraepithelial neoplasia
-screening less effective for CGIN
how is cervical intraepithelial neoplasia diagnosed?
using Colposcopy
Stage I cervical intraepithelial neoplasia?
-Mild dysplasia
-affecting 1/3 thickness of epithelial layer
-likely to return to normal without treatment
Stage II cervical intraepithelial neoplasia?
-Moderate dysplasia
-2/3 thickness of epithelial layer
-likely to progress to cancer if untreated
Stage III cervical intraepithelial neoplasia?
-severe dysplasia
-very likely to progress to cancer if untreated
-Cervical carcinoma in situ
