Pathology - Vagina and cervix Flashcards
What is the upper 1/3 of the vagina derived from?
Mullerian duct - columnar
What happens to the columnar epithelium of the vaginal canal?
Replaced by squamous epithelium from the lower 2/3s (derived from urogenital sinus)
What is adenosis?
Focal persistence of columnar epithelium in upper 1/3 of vagina
What teratogenic drug is associated with adenosis and therefore clear cell carcinoma?
Diethylstilbestrol (DES)
What is clear cell adenocarcinoma associated with?
Vaginal adenosis
What is squamous cell carcinoma of the vagina usually secondary to?
Cervical SCC
- Primary rare
What is sarcoma botryoides?
Embryonal rhabdomyosarcoma variant
- Malignant mesenchymal proliferation of immature skeletal muscle
How does sarcoma botryoides present?
- Females < 4 years old
- Clear grape-like polypoid mass emerging from vagina
- Spindle-shaped cells, desmin +ve
What is significant about rhabdomyoblast on histology ?
- Cytoplasmic cross-striations
- Positive IHC staining for desmin (muscle) and myoglobin
What is the precursor lesion to vaginal carcinoma?
Vaginal intraepithelial neoplasia
Cancer from the lower 2/3s of vagina spreads where?
Inguinal nodes
Cancer from the upper 1/3 spreads where?
Regional iliac
What does the ‘neck’ of the uterus divide?
Exocervix (squamous) and endocervix (columnar)
What is the single line of cells that divide the exo and endocervix called?
Transformation zone
What strains of HPV increase the risk of CIN?
16, 18, 31, 33
What are the 2 gene products produced by HPV which
E6 and E7
What does E6 increase the destruction of? (which can lead to dysplasia etc.)
p53 (inhibits/checks the cell before entering S phase)
What does E7 increase the destruction of?
Rb
What is CIN characterized by (histology)?
- Koilocytic change (nuclear enlargement - halo cells) - raisin appearance
- Nuclear atypia (abnormal nuclei)
- Increased mitotic activity
How can CIN be graded?
Based on extent of immature, dysplastic cells
- First 1/3
- 2nd third
- Last 3rd
- Full way = carcinoma in situ
What is the difference between dysplasia and carcinoma in situ?
Reversibility (grade I reverses 66% of the time, grade II 33%)
- CIS will not reverse
What does carcinoma in situ become?
Cervical carcinoma
- Invasive carcinoma that arises from cervical epithelium
How may cervical carcinoma present?
- Vaginal bleeding (often postcoital)
How may CIN (cervical dysplasia) be identified?
Pap smear
What other than HPV may be risk factor for developing cervical cancer?
- Smoking
- Immunodeficiency
What are the subtypes of cervical cancer?
- Squamous cell (more common)
- Adenocarcinoma
Both related to HPV
Where does cervical cancer classically spread and how does this present?
- Invades through ant uterine wall into the bladder -> blocks ureters causing hydronephrosis (presents with renal failure)
After pap smear (screening test) what test is required for diagnosis?
- Colposcopy
and biopsy
What are the limitations of the pap smear?
- Inadequate sampling of transformation zone resulting in false negatives
- Limited efficacy in screening for adenocarcinoma
Which strains of HPV are covered by the vaccine? and for how long?
Quadrivalent - 6, 11, 16, 18
- Protection lasts up to 5 years
- Pap smears still often necessary
