External quality assurance (EQA) procedures
A certified regulatory body that is qualified to audit the laboratory can perform various forms of EQA. Technical EQA is a scheme in place where the laboratory has a nominated month to send a set of slides for staining evaluation. Screeners from other laboratories perform the evaluation blindly and a score is given. Laboratories that fail […]
Reporting the cytology
Sources of error Principles Reporting rates for high-grade cytology may be compared between pathologists for internal QA or, as a form of external QA between laboratories and regional or national standards. Considerable variation in high-grade reporting rates in nine laboratories, with an overall population of 1 million people, moved close to the target NHSCSP range […]
Glandular abnormalities of the cervix
Adenocarcinoma in situ (AIS) of cervix – high-grade CGIN Although typical cytological features of AIS can be described and recognised, it is impossible to exclude the presence of invasion when these features are seen. In the UK system, high-grade CGIN (AIS) and endocervical adenocarcinoma are collectively described as glandular neoplasia: when glandular neoplasia is diagnosed […]
Squamous cell carcinoma (SCC)
Frankly invasive carcinoma is usually diagnosed in women with symptoms suggesting cancer but cytology may sometimes be taken as part of the investigation. Cytology is regarded as unreliable in clinical cancer because associated haemorrhage and inflammation tends to obscure the nuclear detail. A recent study from the NHS Cervical Screening Programme has shown that cytology […]
Atypical squamous cells cannot exclude HSIL (ASC-H)
The section above describes how to recognise the main presentations of HSIL. ASC-H should be rare if cytologists concentrate on the abnormal chromatin pattern and irregular nuclear membranes seen in HSIL and are aware that In most countries ASC-H is not subjected to HPV triage so the diagnosis depends on colposcopy appearances and accurate biopsies. […]
Four major presentations of HSIL
It is good practice to know the variation in appearances of HSIL. Keratinising Presentation There may be an abundance of material on the cytology preparation due to the mature nature of this dysplasia. Cells appear as sheets with crowded nuclei, overlapping nuclei with single cells dissociating from the groups. In LBC preparations dissociation is […]
High-grade squamous intraepithelial lesion (HSIL)
There is no requirement in TBS to sub-classify HSIL as ‘favour CIN2 or favour CIN3’, or high-grade dyskaryosis as moderate or severe dyskaryosis in the UK system (Denton et al. 2008). The most important distinction to be made on cytology is between LSIL and HSIL. Nevertheless, the UK system and some others in Europe prefer to diagnose […]
Atypical squamous cells of undetermined significance (ASC-US)
In the majority of cases, an experienced cytotechnologist or pathologist can make the distinction between benign epithelial cells and neoplastic cells with a high degree of confidence. However, in what should be a small proportion of cases, there may be genuine doubt as to whether the epithelial cells are benign or neoplastic. In TBS these […]
Squamous cell abnormalities of the cervix
Squamous intraepithelial lesion (SIL) The histological spectrum of CIN is described cytologically as squamous intraepithelial lesion (SIL) is primarily recognised by the abnormal chromatin pattern and nuclear membrane irregularity as described in Table 9c-1 above and referred to in the UK system as ‘dyskaryosis’. The distinction between high-grade and low-grade (HSIL and LSIL) depends on […]
Reactive cytological changes
The effects epithelial injury Injury to the cervical epithelium results in an inflammatory response characterised by localised and systemic changes to the tissue. At the site of injury there is obviously localised damage to the epithelial cells which show degenerative changes to the cytoplasmic and coagulative necrosis of the nuclei. In the underlying stroma we […]