Tejido Epitelial Citomorfologia

Exfoliative cytology for diagnosing oral cancer
M Pérez-Sayánsm, JM Somoza-Martín, F Barros-Angueira, MD Reboiras-López, P Gándara-Vila, JM Gándara Rey, A García-García
School of Dentistry, Entrerríos s/n, Santiago of Compostela C.P 15782, Spain .
Accepted June 22, 2009

Abstract
Exfoliative cytology is a minimally invasive technique for obtaining oral cell specimens from patients for diagnosticpurposes. Classical applications of oral cytology studies, such as oral candidiasis, have been extended to include oral precancerous and cancerous lesions. A number of analytical methods are available for studying cytology specimens. The development of molecular analysis techniques, the oral cancer etiopathogenic process, and improvements in liquid-based exfoliative cytology are leading to renewedinterest in exfoliative cytology. Results sometimes are disputed, so the aim of our review was to clarify the applicability of exfoliative cytology to the diagnosis of oral precancerous and cancerous lesions.
Key words: liquid-based cytology, molecular analysis, oral cancer, oral cytology, quantitative

cytomorphologyr

Classical diagnostic methods for precancerous and cancerous oral lesionsinclude clinical examinations and histopathological studies of biopsied material (Acha et al. 2005, Hullmann et al. 2007). Obtaining a sample by biopsy is invasive and involves both technical difficulties and psychological implications for the patient. When the lesions are extensive, the most representative areas must be selected to avoid diagnostic errors. Biopsy has poor sensitivity owing to thesubjectivity of the pathologist (Epstein et al. 2002). It is important to simplify diagnostic techniques to enhance their reliability and to reduce their invasiveness to improve diagnosis and follow-up for patients with precancerous and cancerous oral lesions. In recent times we have witnessed a growing interest in different kinds of oral cytology methods (Acha et al. 2005).

Concept
Exfoliative oralcytology is the study and interpretation of the characteristics of cells that flake off, whether naturally or artificially, from the oral mucosa. After the cells have been collected, fixed and stained, the morphology of surface epithelial cells is observed under a microscope (Langlois et al. 1993). The technique is simple, non-aggressive, relatively painless and tolerated well by patients(Driemel et al. 2007). It can be used for diagnosis of predictive methodology and identification of recurrent oral squamous cell carcinoma (SCC) (Moralis et al. 2007). Papanicolaou and Traut (1941) first demonstrated the validity of cytology for diagnosing neoplasms of the uterine cervix. Oral cytology soon came to be used for diagnosis of diseases of the oral cavity, although with little success(Sandler 1963). The presence of histological changes in the oral mucosa (lining, and special masticatory mucosa) sometimes creates difficulties for diagnostic pathologists who do not specialize in oral tissues. Cells are obtained from the oral cavity using physical procedures such as surface scraping or brushing, rinses, or saliva specimens. The gold standard is exfoliation by mechanical separation ofepithelium using different instruments to which 177

Correspondence: Mario Pérez-Sayánsm, DDS, Facultad de Odontología, Entrerríos s/n, Santiago de Compostela C.P. 15782, Spain. Tel: 0034626233504. Fax: 0034986295424. e-mail: perezsayans@gmail.com © 2010 Biological Stain Commission Biotechnic & Histochemistry 2010, 85(3): 177–187.

DOI:10.3109/10520290903162730

the term, exfoliative cytology,alludes (Chandler 1966). To obtain oral cells with brushes, we can whisk with a moderately stiff brush (may not reach the basal cells) and the “cytobrush,” which gently excavates down to some of the basal cells. The presence of basal cells is important to RNA collection and analysis, and for diagnostic accuracy. A number of studies have been undertaken to evaluate the use of different instruments...