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
Explain the Endocervicals
- The ectocervix is exposed to the acidity of the vaginal canal. (most infections like alkali conditions)
- Because of the fragile nature of endocervical cells, when they are exposed to this acid environment the cells undergo transformation into squamous cells to offer protection . This process is continuous, it is “normal” and is known as squamous metaplasia.
Recognising Squamous metaplasia
Recognised by a dense opaque blue cytoplasm and bizarre shapes/forms.
Where do the endometrial cells shed from?
Explain endometrial cells
- Higher in the uterine body we find glandular cells called endometrials.
- These cells are seen “normally” at days 1- 14 and days 26-27 of the menstrual cycle it is therefore important for the patient to know the 1st day of her last menstrual period.
- If LMP is unknown, the patient is over 40 , and these cells are present they will be treated as suspicious and the patient will be referred for further treatment in gynaecology.
Explain INFECTIONS IN CERVICAL SAMPLES
- All infections produce an excess of white blood cells (usually polymorphs) which can be troublesome when screening.
- They can obscure the cells and make the sample “inadequate” for interpretation and a repeat test will be requested by the laboratory.
Histology of polymorphs
Common infections in female reproductive tract
- Infections are mainly sexually transmitted.
- Some are more easily treated than others.
- The most commonly observed will be discussed:
1.Trichomonas Vaginalis: –
Can infect both men and women and patients present with a yellow /green foul smelling discharge. It is a parasite and has no link to cervical cancer.
2. CANDIDA ALBICANS (THRUSH)
- A yeast infection which occurs mainly in 16-35 year old women.
- Hyphae and spores can be observed which stain red. Inflammatory changes often occur alongside infection.
- Treatable with drugs or cream (canesten)
3. ACTINOMYCES LIKE ORGANISMS/ ALO’s.
- These are related to true bacteria and are found in women using Intra Uterine Contraceptive Devices (IUCD).
- They usually appear as dark dense clusters with a central core and filaments protruding from the structure. The filaments aid in their identification.
- They are not linked to cervical cancer.
4. HERPES SIMPLEX VIRUS (HSV)
- There are 2 types of the virus: Type 1- found on the lips and nose Type 2-found on the genitalia.
- It is sexually transmitted and incurable.
- Appears cytologically as large multinucleated cells with dense central cores.
5. HUMAN PAPILOMA VIRUS (HPV)
- One of the most common infections
- It is a viral particle that has 100’s of variants some of which are causative of cervical cancer.
- Viral strains 6 ,and 11 are found in low grade lesions and don’t usually progress to cervical cancer, whereas strains 16 and 18, have been found to be present in almost all cervical cancers.
- It has been found that repeated and/or prolonged infection with High Risk HPV can lead to cervical cancer.
- Under certain conditions the virus can invade and interrupt the normal cell cycle leading to the “turning on” of uninhibited cell growth with the involvement of oncogenes E6 and E7.
Explain Trichomonas Vaginalis:
Can infect both men and women and patients present with a yellow /green foul smelling discharge. It is a parasite and has no link to cervical cancer.
Explain CANDIDA ALBICANS (THRUSH)
2. CANDIDA ALBICANS (THRUSH)
- A yeast infection which occurs mainly in 16-35 year old women.
- Hyphae and spores can be observed which stain red. Inflammatory changes often occur alongside infection.
- Treatable with drugs or cream (canesten)
