Guidelines for reporting abnormal cytology
While describing the features of the spectrum of squamous and glandular abnormalities seen in cervical cytology and histology it is essential to use terminology that is understood by everyone involved in the screening process and for results to be comparable to those reported in other regions and countries. Much of the world uses the Bethesda […]
Collecting, preparing and fixing the cellular samples
Sources of error A chapter has been dedicated to guidelines for taking a cellular sample, fixing and processing conventional and liquid-based preparations. Here we discuss sources of error during this stage in the process. Clinical condition of the patient at the time of sampling Samples taken during, or in the few days before or after, […]
Cytological screening
The ability to screen a predominantly negative cytology slide and notice occasional abnormalities among many thousands of cells requires specialist training, knowledge of the nature of normal and abnormal cells, and concentration and dedication. Here we deal with sources of error in screening and how they can be avoided. Sources of error Personal reasons […]
Distinguishing progressive from reversible lesions
Cytological screening has been so successful in preventing invasive cervical carcinoma that its importance as a health problem tends be overshadowed by the disadvantages and possible risks of screening itself. In England, where screening coverage since the NHS Cervical Screening Programme was officially launched in 1988 has been high, CIN3 has most frequently been found and […]
11. Quality assurance, quality control and quality standards
Quality assurance The maintenance of a desired level of quality in a service [or product] especially by means of attention to every stage of the process of delivery or production (www.oxforddictionaries.com) In order to maintain the desired level of quality in cervical cancer screening, the following systems are required: Quality control: internal measures to […]
References
Arbyn M, Ronco G, Anttila A et al. (2012). Evidence regarding human papillomavirus testing in secondary prevention of cervical cancer. Vaccine 30 (suppl. 5):F88-99. Arbyn M, Roelens J, Cuscheiri K et al. (2013). The APTIMA HPV assay versus the Hybrid Capture 2 test in triage of women with ASC-US or LSIL cervical cytology: a meta-analysis […]
Potential risks of treatment of high-grade CIN
Local ablation or excision of the transformation zone has been highly successful in treating high-grade CIN and greatly reduces the risk of progression to invasive carcinoma but it is not itself without risk (Kyrgiou 2014). It is probable that the increase in second trimester miscarriages due to premature rupture of membranes reported after excision biopsy […]
Uses of HPV testing in triage of cervical cytology
Uses of HPV testing alongside cytology Triage of ASC-US and/or LSIL cytology Test of cure after treatment of high-grade CIN Resolution of uncertainties Primary HPV testing or co-testin The principles of all these methods alongside cytology are similar: HPV is more sensitive than cytology for CIN2+ Early detection of CIN2 is not an end […]
Measurement of accuracy
Measurement of accuracy Measurement of accuracy of screening combines sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of a positive test with respect to a positive outcome (Figure 5.5). The following factors must be considered when assessing measurements of accuracy. The nature of the positive and non-positive test for any given circumstance […]
8. Collecting and processing cellular samples from the cervix
Guidelines for taking cellular samples Guidelines are available for taking samples for conventional cytology or liquid-based cytology, which are equally effective as long as the guidelines are adhered to (NHSCSP 2006); Arbyn et al. 2007). Clinical conditions required for taking a sample Cytology samples should be taken at mid-cycle: menstrual samples may obscured by […]