Purpose and scope

The purpose of this book is to focus on effective strategies to deal with everyday difficulties in recognising and diagnosing high grade lesions, and distinguishing them from their mimics. The strategies and criteria developed here should not be seen as replacing existing effective strategies and criteria, but as providing added information to assist with the challenge of confronting difficult cervical cytology.

Section 1 provides an overview of the reasons why cervical cytology can be difficult, and presents an approach to diagnosis based on the detection of high risk patterns during screening, and their objective evaluation, with special emphasis on nuclear variation.

Section 2 provides examples of a wide range of high risk patterns readily detectable during screening on low power. It emphasises specific tests to apply to high risk patterns, and strategies that add objectivity to the decision making process. It also fine tunes the criteria used for interpretation of difficult cases. Illustrations of individual difficult cases are included throughout.

This work is not a comprehensive text in gynaecological cytology. It assumes knowledge of relevant terminology, the biology of the normal and abnormal cervix, and the standard criteria used in cytodiagnosis. Although developed in conjunction with a workshop on difficult gynaecological cytology, the book stands independently as an educational resource and reference, to support practising cytology professionals in their confrontation with difficult cases. Its content is based on conventional smear appearances. Cytologists examining thin layer preparations should be mindful of the differences in appearances between thin layer preparations and conventional smears. Nevertheless, most of the concepts and strategies in this document apply to either context.

All high grade abnormalities presented here have been confirmed by histology. Cases presented as benign have had at least two subsequent negative investigations.