cervical pathology

Question 1

explain the histological and cytological grading of precancerous cervical squamous lesions

Answer 1

histological:
- HPV, CIN 1, CIN 2, CIN3
cytological:
- low grade squamouns intraepithelial lesion (HPV and CIN1) and high grade squamous intraepithelial lesion (CIN2 and 3)

Question 2

where is the highest incidence of cervical cancer in the world

Answer 2

south america, africa and india

Question 3

explain the correlation between HPV and different types of cancers

Answer 3

cervical - 100% attributable to HPV
penile or vulval - about half
oropharyngeal - lowest proportion

Question 4

what are the 2 highest risk HPV to go on for cervical cancer

Answer 4

16 and 18

Question 5

which age group has the biggest prevalence of HPV infection

Answer 5

20-24

Question 6

describe the structure of the HPV virus

Answer 6

dsDNA with capsid

Question 7

explain the two classes of proteins that are made by HPV

Answer 7

early = encode for replication and viral proteins
late = encode for capsid proteins

Question 8

what type of cells does HPV infect

Answer 8

the immature basal cells of the squamous epithelium in areas of epithelial breaks or immature metaplastic squamous cells present at the squamo-columnar junction

Question 9

explain what integration of the HPV genome into host DNA does

Answer 9

• during replication - a break point is introduced into the E2 gene (usually suppresses E6 and E7.
• break in E2 disrupts the gene which causes regulation of E 6 and E7 to be lost
• E6 binds to p53 and deactivates it
• E7 binds to Rb and disrupts its ability to halt cells at the restriction point
• allows neoplastic cells to proliferate

Question 10

what proportions of HPV viral infections are cleared

Answer 10

50% are cleared within 8 months

90% are cleared within 2 years

Question 11

which area of the cervix is most susceptible to dysplasia and HPV infection

Answer 11

the squamocolumnar transformation zone

Question 12

what is a cervical condyloma

Answer 12

the cells are infected with HPV but hasn’t been integrated into the host genome - causing squamous cell layer thickening and keratinocytes can retain their nuclei

Question 13

what defines CIN 1,2,3

Answer 13

CIN 1 = atypical changes involve only the lower 1/3 of the epithelium
CIN 2 = involves up to 2/3 of the epithelium
CIN 3= involves between 2/3 and the whole width of the epithelium

Question 14

when does CIN 3 become squamous cell carcinoma

Answer 14

with invasion of the BM

Question 15

what are the histological features of adenocarcinoma in situ

Answer 15

• nuclei haphazardly arranged
• numerous mitotic bodies
• apoptotic debris
• cells have lost polarity
• nuclei polymorphism

Question 16

what do koliocytes look like

Answer 16

have large vacuole within the cell

Question 17

what can you see on cytology for low grade and high grade squamous intraepithelial lesion

Answer 17

low = koliocytes
high = markedly enlarged nuclei with minimal cytoplasm, pleomorphism more significant

Question 18

what are the guidelines if a cervical smear is normal

Answer 18

repeat in 2 years

Question 19

what are the guidelines if a cervical smear is unsatisfactory

Answer 19

repeat in 6-12 weeks

Question 20

what are the guidelines if a smear has possible LSIL/LSIL

Answer 20

repeat pap test in 12 months

Question 21

what are the guidelines if a smear is possible HSIL / HSIL / repeated LSIL

Answer 21

referral for colposcopic assessment