Cervical Screening and Vulval Pathology Flashcards
Ho do the linings of the ectocervix and the endocervical canal differ?
Ectocervix - lined by squamous epithelium (same as vagina)
Endocervical Canal - lined by glandular epithelium
What cells in the squamous lining of the ectocervix proliferate?
Basal cells
- the cells mature and move upwards to surface (like in the skin)
What cells does a cervical smear test remove?
Mature surface cells of ectocervical lining
Why is there a Transformation Zone in the cervix rather than a squamo-columnar junction?
Location of squamocolumnar junction changes over time Due to: - menarche - Pregnancy - menopause
=> area between the original SC Junction and the New SC junction is the Transformation Zone
What causes erosion of the endocervical tissue causing it to undergo squamous metaplasia?
acidic environment of vagina
What are Nabothian follicles and are these benign or malignant lesions of the cervix?
- dilated endocervical glands
- form almost polypoid-like structure
- Benign
What percentage of Cervical Intraepithelial Neoplasia (a precursor to cancer) occurs in the Transformation Zone?
90%
What inflammatory pathologies can present in the cervix?
Cervicitis
- often asymptomatic
- can lead to infertility due to silent fallopian tube damage
- non-specific acute/chronic inflammation.
Cervical polyp
- localised inflammatory outgrowth,
- Cause of bleeding, if ulcerated
- Not premalignant
What can cause cervicitis?
Chemical Irritants
Infection e.g. Chlamydia, Herpes Simplex
What neoplastic pathologies can present in the cervix?
- Cervical Intraepithelial Neoplasia (CIN)
- Cancer
=> Squamous carcinoma
=> Adenocarcinoma
What is the most important risk factor for development of neoplastic pathology in the cervix?
High Risk Human Papilloma Virus (HPV) types
- 16,18 = highest
(31,33,35,45,48…)
What other risk factors exist for CIN and cervical cancer?
- many sexual partners = increased risk of acquiring high risk HPV subtypes
- younger age of first intercourse/pregnancy
- long term use of oral contraceptives
- non-use of barrier contraception
- Smoking: 3 x risk
- Immunosuppression
How do genital warts appear on histology?
- thickened “papillomatous” squamous epithelium
- Cytoplasmic vacuolation
- Koilocytosis => Nuclear enlargement (2-3x normal size) and Irregularity of the nuclear membrane contour
How does the appearance of CIN differ from that of genital warts?
- Affected epithelium remains flat (unlike wart)
- shows koilocytosis, which can be detected in cervical smears
CIN is graded from 1-3 with Grade 3 being the most severe. What is Grade 3 CIN homologous to?
Carcinoma in situ
When does CIN 3 thought to become a cancer on microscopic analysis?
When the cells break through the basement membrane to invade the stroma
How long does it usually take for HPV infection to progress to CIN 3, and how long for CIN 3 to progress to cancer?
HPV infection to High grade CIN:
=> 6 months - 3 years
High Grade CIN to Invasive Cancer
=> 5 -20 years