intro to cervical screening test Flashcards
HPV DNA LR (low risk) & HPV DNA HR (high risk)
- LR: 6 & 11
- HR: 16 & 18
Squamous layers of the cervix
- Keratinising layer: keratinised cells w/ karyorrhexis & karyolysis
- superficial layer: small nuclei
- Intermediate layer: larger nuclei
- Parabasal layer: Hi NC ratio
- Germinal layer: basal/reserve cells
morphology of parabasal cells
- round - oval
- cyanophilic (dense green) cytoplasm & may stain orangeophilic if not preserved well
- nucleus is 50% of cell, fine chromatin pattern
- present in sheets or single
- Significant no. = oestrogen deficiency in postmenopausal/partum women
morphology of intermediate cells
- polygonal shape & larger than parabasal
- blue/green cytoplasm (if well preserved)
- fine chromatin & even distribution (vesicular nuclei)
morphology of superficial cells
- larger (than intermediate cells), flat, polygonal shape
- cytoplasm light pink - orange
- pyknotic nuclei
morphology of endocervical cells
- strips, sheets, single
- honeycomb appearance if in flat sheet
- OR palisaded (picket fence) arrangement
- cyanophilic cytoplasm (green)
- round nuclei @ base, fine chromatin pattern, 1-2 nucleoli
morphology of squamous metaplasia (*features that make it stand out from paranasal)
- similar size to parabasal
- vesicular round-oval nuclei
- *polychromasia (blue & pink)
- *spinous processes
During a womans mens. cycle what are the types of endometrial epithelial cells described & where they are found
- superficial stromal
- deep stromal
- Central core of stromal cells
- direct endometrial sampling on higher isthmus in endometrium
- exfoliated endometrial cells found in cervical & vaginal secretions
A smear is considered unsatisfactory if (a).
An unsatisfactory smear may be due to (b. 6)
a. >75% cells are obscured that NO abnormal cells are identified
b. - insufficient cell. material
- poor fixation => may result in formalin vapour artefact
- poor collection technique
- heavily blood stained
- marked inflammation
- mucus present
Principle of papanicolauo stain
- Harris haematoxylin= nuclei blue
- orange green 6= cytoplasm of mature, keratinised cells orange
- Eosin azure= mature squ. cells pink & parabasal, intermediate & columnar cells light green
6 Steps for Koeholer illumination
- focus on a slide on 10x objective w/ both eyes (RHS & LHS)
- Close field diaphragm till you can see the edges if the diaphragm
- using condenser focus knob, bring edges of diaphragm to a sharp focus
- centre the image using condenser centring screws
- Open field diaphragm just until it’s out the FOV
- adjust condenser iris diaphragm to 0.5 > optimum contrast
Why has the CST screening age changed from 18 to 25yo? & an exception
a) bc they found that women <25yo had genital HPV- associated w/ low risk variants of HPV (6 & 11 - low risk)
=> not at risk for developing cervical cancer at that age
b) if showing symptoms they must get tested for HPV DNA: +ve result means follow up w/ LBC reflex; -ve result means 5yr screen
Prepare plasma/thrombin cell block
- cell suspension centrifuged
- supernatant is aspirated (removed) & cell deposit is mixed w/ plasma
- Add & mix thrombin in
- clot forms & retract
- Add NBF => processing & sectioning
3 dis&advantages of cell block prep
Adv: inexpensive; suitable for FNA, easy method; maintain architecture - resemble surgical specimen; indefinite storage; special stains; architectural features
Dis: time-consuming, not work on small samples, cross-contamination from plasma & thrombin; can’t determine invasiveness of tumour
dis&adv. of diagnostic cytopathology
Adv: non-invasive, accurate, inexpensive, rapid
Dis: less info. than biopsy, adequate sampling can be problematic
