Molecular techniques in cytopathology practice

In the last decade, new molecular techniques were introduced into pathology laboratories. Cytology also benefited from the innovations emerging from this new era. Molecular cytopathology (MCP) can be defined as molecular studies applied on all types of cytological specimens, namely gynaecology cytology, exfoliative non- gynaecology cytology and fine needle aspirates. The development of many new ancillary techniques has paralleled the emergence of clinical cytology as a major diagnostic specialty. Clinical applications of these techniques have been growing in the last decade. The widespread acceptance of liquid-based systems in gynaecological cytology emphasises the relation between cells and molecules. The increased use of morphology and molecular biology in human papillomavirus-induced lesions for example, showed the potential to optimise, in one single brushed sample, diagnosis and research. Cytology samples from serous effusions, the pulmonary tree, urine, and aspirations, among others, are now likely to be studied by different molecular techniques for diagnosis, prognosis, or even assessment of therapeutic targets. In this review, the main published results concerning the application of molecular techniques in different fields of cytopathology are highlighted, and their applications discussed.