L6 - Diagnostic Cytology Specimens,Theory & Gyn Cytology Flashcards
1
Q
Why do we do cervical screens?
A
- Reduce the incidence of cervical cancer
- Screening guidelines differ at an international level from 1 to 5 years
- In Australia we used to screen every 2 years if a screen was negative
- as of Dec 2017, if a patient is HPV DNA neg for HR HPV, they will not require a HPV or reflex pap test for 5 years
2
Q
Renewal of the National Cervical Screening Guidelines
A
- 5 yearly cervical screening with HPV DNA and partial HPV genotyping with and without reflex LBC in vaccinated and unvaccinated women
- Self collection a HPV sample for underscreened women facilitated by a nurse or GP
- Invitations/reminders sent out to women aged 25 - 74 for screening
- Delisting of the existing cervical screening MBS items
3
Q
Sampling the cervix
A
Materials required:
- Cervex brush
- Wooden Ayre’s spatula
- Endocervical brush
- Most premalignant and malignant lesions occur in the transformation zone
4
Q
How conventional smears are prepared
A
- As soon as the smear is completed fix the slide in cytofix (2.5 PEG fixative)
- Fixed in 95% alcohol in a coplin jar
- Fixation should occur within 30 seconds to prevent drying out
- Cervical smears are always stained with the Papanicolau stain
5
Q
Papanicolau Stain
A
- A polychromatic stain uses multiple dyes to differentially stain different components of the cell
- includes both acidic and basic dyes
- haematoxylin stains the nucleus blue
- OG6 is the first acidic component and stains mature and keratinised cells, the target structures are stained orange
- EA50 is the second acidic counterstain and gives a pink colour to the cytoplasm of mature sqaumous cells, nucleoli and RBCs
6
Q
Preparation methods
A
- Conventional pap smears
- Liquid based samples
- Screening methods
7
Q
Liquid based methods
A
- thin prep samples
- surepath
8
Q
Screening methods
A
- cytologist - incorporates human error
- interactive automation (thin prep imaging system, focal point slide profiler)
9
Q
Vulva
A
- Labia majora
- Labia minora (many sebaceous and apocrine sweat glands)
- keratinising squamous epithelium
10
Q
Vagina
A
- Stratified non-keratinising squamous epithelium
- mucosa is subject to cyclical changed under the influence of sex hormones
- fibrovascular sheath
- no glands
11
Q
Uterus
A
- pear shaped organ
- body/corpus and cervix
- perimetrium (serosa)
- myometrium (smooth muscle)
- endometrium
12
Q
Cervix
A
- cylindrical fibromuscular structure
- endocervical canal connects the body of the uterus at the internal os with the vagina at the external os
- protrudes into the vagina - posterior, anterior, and 2 lateral fornices
- ectocervix is the other aspect of the cervix covered by squamous epithelium
- endocervical canal - tall columnar cells with inconspicous reserve cell layer underneath
- squamo-columnar junction is where the squamous epithelium of the cervix meets the endocervical canal
13
Q
Endocervical canal
A
- Tall mucus secreting columnar epithelial cells
- Highly branched tubular and cervical glanda
14
Q
Portio vaginalis
A
- Germinal layer: adheres to basement membrane
- Parabasal layer: immature and crowded
- Intermediate layer: variable thickness
15
Q
Endometrial histology
A
- Endometrium: thin basalis layer which is next to the myometrium
- the functional layer is superficial, compact layer has few glands and abundant stroma
- deep layer or spongiosa with abundant glands and less stroma
