Cytopathology of the female genital tract Flashcards
What is Cervical cytology?
Cervical cytology is the study of cells from the cervix.
It is used to reduce the incidence of cervical cancer by detecting pre –invasive lesions.
Early detection has proved to decrease mortality from cervical cancer.
What is the effect of screening?
Graph showing that as coverage (pink) increased the death rate (red) decreased.
Who has cervical screening?
All women aged 25-64 were invited for screening at 3 to 5 yearly intervals depending on their age.
What was done to increase cervical screening?
Financial incentives were set up for GP surgeries in order to obtain high population coverage. GP’s were effectively paid for taking cervical smears.
What is the role of cytology?
Cytology is the study of cells and is used to detect abnormalities in cells from the cervix that are dyskaryotic or pre-cancerous.
These changes are graded from borderline to severe dyskaryosis and depending on both persistence of abnormality or severity, women will be referred into colposcopy for further treatment.
What is the role of Colposcopy?
- Colposcopy is used to obtain tissue samples of the cells that have been called abnormal on cytology.
- These samples are graded as Cervical Intraepithelial Neoplasia and grades range from 1 to 3 depending on their severity.
- Any major discrepancies between the cytology and histology result are discussed at a Multidisciplinary meeting where patient follow up and treatment are decided.
What is used for the method of sample collection, fixation, preparation and screening in cervical cytology?
LBC (Liquid Based Cytology)
How sample taking for LBC?
Cells are removed from the cervix using the “cervex”™ brush and a 360 ° rotation of the cervical os and ectocervix . This is repeated 5 times . Previously this was done using the aylesbury spatula
What is sample fixation?
The cells collected on the brush are placed immediately into a pot of alcohol based preservative fluid. This is to prevent “drying out” of the sample which can cause diagnostic problems when screening.
Explain sample processing
A Hologic T5000 ™ fully automated processing machine prepares the samples producing a circular preparation of the cells onto a slide. These are then stained with the Papanicolau staining technique on a fully automated platform.
What is the request card for cervical screening?
- An HMR101 form or electronic ICE request is completed with the patient details which must match those on the sample pot and both are sent to the laboratory for processing.
- If there are any discrepancies between the form and the pot they will not be accepted by the laboratory.
How screening works?
Slides once prepared are matched with their request cards and screened.
Each slide takes approximately 5-12 minutes to screen depending on the difficulty of the case.
What are screening staff looking for?
- Normal samples make up the majority of our workload.
- Therefore we need to know what features are “normal” to know what are “abnormal”.
- Indicators of abnormality are :
- increased nuclear/cytoplasmic ratio,
- irregular nuclear outline,
- hyperchromasia (darkening) of nuclear chromatin, and bi/multi nucleation of cells.
Explain the cervical epithelium
- The cervical epithelium is structurally the same as any other skin surface on the body but is the only one that responds to changes in oestrogen levels during the menstrual cycle.
- At day 14 of the menstrual cycle oestrogen levels peak and the cervical epithelium achieves full thickness. This offers protection against infection and therefore this is the “optimal” time to take the sample.
- When Oestrogen levels are high the cervix “bulks” up and causes the cells from the endocervical canal to evert out over the ectocervix and form a reddened area.
- This is known as an ECTROPIAN and is a normal condition.
- The cells causing the red area are endocervical cells from the canal.
Histology of Endocervical Cells