Cervical Screening + Cervical Cancer Flashcards
what is HPV?
Human Papilloma Virus
- main cause of cervical cancer
peak prevalence of HPV?
15-25 years but prevalence reduces with age
what is HPV infection of cervix associated with?
changes in the epithelium called cervical intraepithelial neoplasia (CIN)
what is CIN and what may it be a precursor to? (not always)
- abnormal proliferation of cells in squamous epithelium (neoplasia = new cells) which is invisible to naked eye
- precursor to invasive cancer
outline the grading of CIN
- grade 1
- 1/3 of thickness of surface layer affected
- grade 2
- 2/3 of thickness of surface layer affected
- grade 3
- full thickness of surface layer affected
what may happen to CIN?
may regress, remain unchanged or persist
what % of grade 3 CIN goes on to become invasive cancer?
20% over 10-20 years if left untreated
outline when screening takes place and what is the medium used
- every 5 years from 25-64 years old
- liquid based cytology
outline the process of screening
- samples are tested for HPV infection
- If HPV negative
- recall again in 5 years time for routine screening
- If HPV positive
-
reflex cytology of sample
- if cytology normal= repeat test in 1 year
- if cytology abnormal = Colposcopy
-
reflex cytology of sample
- If HPV negative
where is it important to take a smear from and why ?
transition zone of cervix
- because CIN occurs mainly in squamocolumnar junction - between sqamous cells of ectocervix and columnar cells of endocervix
- is the site of HPV infection
what happens in the transformation zone with CIN?
columnar cells of endocervical epithelium are transformed into squamous cells
what is cervical cytology?
- microscopic assessment of cells scraped from transformation zone
- looking for abnormal cells (dyskaryosis), which is suggestive of underlying CIN
what are benign nuclear features?
- small
- fine regular chromatin
- equal size/shape
what are abnormal nuclear features?
- increase in nucleus: cytoplasmic ratio
- variation in size / shape
- coarse, irregular chromatin
- nucleoli
how is dyskariosis graded?
high or low grade
- reflects degree of underlying CIN
what is colposcopy and what options do you have while you are doing it?
magnification + light to see the cervix
Options:
- punch biopsy –> to make diagnosis
- if CIN 2/3 come back another time to treat
How does HPV infection affect the epithelial cells of cervix?
- infects basal layer
- uses host for replication
- when host cell matures–> expression of viral genes
what is the appearance of HPV on histology?
- koilocytes
- cells with wrinkled nuclei + perinuclear halo
- multinucleated
risk factors for CIN?
- HPV infection (types 16 and 18)
- early age of 1st intercourse
- multiple sexual partners
- prolonged OCP use
- smoking
- STD
- immunodeficiency
- persistent infection
Treatment of CIN?
- LLETZ
- Large Loop Excision of Transition Zone
- thermal coagulation
- laser ablation
what is the epidemiology of cervical cancer?
mostly women 45-55
risk factors of cervical cancer?
- HPV
- early age of 1st intercourse
- multiple sexual partners
- smoking
symptoms of cervical cancer?
- abnormal vaginal bleeding
- discharge
- pain
- IMB / post-coital
diagnosis of cervical cancer?
- asymptomatically - screening
- clinical - symptoms + examination
- BIOPSY
- staging
- PET-CT
- MRI
- EUA (examination under anaesthesia)
management of cervical cancer?
- Radical Hysterectomy
- removal of upper vagina, cervix, uterus and pelvic nodes MINUS ovaries
- chemotherapy
- radiotherapy
