Cervix Flashcards
What are the three parts of the cervix and which cells are in each layer?
Exocervix- non keratinizing squamous epithelium
Endocervix - single layer of columnar cells
Transformation zone
What type of virus is HPV and where does it attack? How is infection eradicated? What does it increase the risk of?
Sexually transmitted DNA virus tha tinfects the lower genital tract, especially the cervis in the transformation zone. Infection usually eradicated by acute inflammation. Persistent infection can lead to increased risk of cervical dysplasia. (Cervical Intraepithelial Neoplasia)
Which HPV types are high risk for Cervical Intraepithelial Neoplasia?
16, 18. 31, 33
Which HPV types are low risk for Cervical Intraepithelial Neoplasia?
6 and 11
What are two products of high risk HPVs and what do they cause?
They produce E6 and E7 which result in increased destruction of p53 and Rb respectively which increases the risk for CIN.
What is Cervical Intraepithelial Neoplasia characterized by?
Koilocytic change, disordered cellular maturation, nuclear atypia and increased mitotic activity within the cervical epithelium.
What are the 4 grades of Cervical Intraepithelial Neoplasia and what do they involve?
Divided based on extent of epithelila involvment by immature dysplastic cells.
CIN I involves < 1/3 of the thickness of the epithelium
CIN II < 2/3 of the thickness of the epithelium
CIN III involves slightly less than the entire thickness of the epithelium
Carcinoma in situ involves entire thickness of the epithelium
A 45 year old back up dancer presents with vaginal bleeding after having sex. She says she sometimes gets cervical discharge instead of the bleeding. What type of carcinoma is she at risk of? What is a key risk factor? What are the two most common subtypes?
She has cervical carcinoma which is an invasive carcinoma that arises from the cervical epithelium. Key risk factor is high risk HPV infection. Secondary risk factors include smoking and immunodeficiency. Most common types are squamous cell carcinoma (80% of cases) and adenocarcinoma (15 % of cases) which are both related to HPV infection.
How does cervical carcinoma progress and how does it cause death?
Advanced tumors often invade through the anterior uterine wall into the bladder, blocking the ureters. Hydronephrosis with post renal failure is a common case of death in advanced cervical carcinoma.
How long does it take for CIN to progress to carcinoma? When does screening begin? What is the gold standard for screening? What is an abnormal test followed by?
10 - 20 years. Screening begins at age 21 and is initially performed every three years. Pap smear. Confirmatory colposcopy and biopsy.
Where are cells obtained for Pap smear and what do they look like under the scope?
From transformation zone using a brush. High grade dysplasia is characterized by cells with hyperchromatic (dark) nuclei and high nucleus to cytoplasmic ratios.
How can HPV infection be prevented?
Immunization
What does the vaccine for HPV cover? What are the antibodies generated against?
Quadrivalent vaccine covers HPV types 6, 11, 16 and 18. Antibodies generated against types 6 and 11 protect against condylomas and antibodies against 16 and 18 protect against CIN and carcinoma.
