The whole slide should be examined carefully to look for recognizable HSIL to avoid unnecessary ASC-H reports.
ASC-H is reported when features of HSIL are uncertain after consideration of all the conditions discussed above as potential false negatives and false positives.
It is easy to see how Figures 10.1 (b), 10.2 (a-b) and 10.3 (a-c) could have been reported as ASC-H if these cells were representative of the most abnormal cells on the slide. Indeed, some of them were reported as ASC-H, which may avoid false negative reports in difficult cases.
Equally, in some examples of immature squamous metaplasia, tubal metaplasia and lower uterine segment sampling it may be difficult in practice to avoid an ASC-US or ASC-H report – as in Figures 10.5 (c-d), 10.6 (b), 10.8 (b) and 10.9 (b).
Colposcopy and slide review of cytology and histology can avoid unnecessary treatment in potential false positive cytology cases.
Monitoring HSIL rates for laboratories and individuals can be used as a method of quality control.
Atypical glandular cells (AGC)
AGC presents a two-fold problem in the context of false negatives and false positives:
Distinguishing benign or metaplastic processes from neoplastic glandular cells as in Figure 10.11 (a-b).
Distinguishing reactive glandular cells from HSIL as in Figure 10.5 (c).
Classical features of AIS must be distinguished from reactive endocervical cells, tubal metaplasia and TEM by attention to the chromatin pattern, palisading arrangement of cells and absence of stromal cells or cilia.
Clinico-pathological correlation and slide review before treatment is the key to avoiding over- or under-treatment of ‘difficult’ glandular abnormalities.
Search the slide for more obvious HSIL or CGIN before reporting the slide
Discuss difficult cases with colleagues before sending out ASC-H or AGL reports
Colposcopy and multidisciplinary review of histology and cytology slides can avoid unnecessary treatment in atypical cases
Remember that judicious use of ASC-H and AGL categories can avoid false positives and false negatives
Learning points from Chapter 10
Dyskaryosis should be present in all false negative and absent in all false positive cellular abnormalities (at least on review)
ASC and AGL (borderline) reports should only be used for genuine doubt between negative/reactive and SIL/neoplasia
False negatives can be avoided by familiarity with their main causes: sparse, pale and small cell dyskaryosis, hyperchromatic crowded cell groups, and dyskaryosis masked by inflammation
Hyperchromatic crowded cell groups and sparse dyskaryotic cells are potential false negatives in LBC as well as conventional smears
False positives may be avoided by familiarity with the full spectrum of reactive changes in metaplastic and inflammatory conditions
Endocervicitis, atrophic vaginitis, immature squamous metaplasia, tubal metaplasia and tuboendometrioid metaplasia are important potential false positives
False positives are important because unnecessary excision biopsy may increase risk of premature rupture of membranes in pregnancy
Atypical/borderline reports when used in cases of genuine doubt may avoid false negatives and false positives
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