Utility of brush cytology in evaluation of pre-malignant and malignant oral mucosal lesions among dental patients attending Kenyatta National Hospital

Abstract

Objectives: The main objective was to determine the utility of brush cytology in evaluation of pre-malignant and malignant oral mucosal lesions.

Methodology: This was a prospective cross sectional descriptive study which was carried out at Kenyatta National Hospital (KNH), Dental clinic, Surgery unit and University of Nairobi, Dental Hospital (UoN DH) from November, 2015 to April, 2016 after obtaining ethical clearance from Kenyatta National Hospital – University of Nairobi Ethics and Research Committee (KNH-UoN ERC) on participants who presented with pre malignant and malignant oral lesions. Participation in the study was voluntary and an informed consent was obtained from all participants. A structured questionnaire was used to collect socio-demographic information and clinical history. A cervical cytobrush brush (Andwin Scientific – Woodland Hills, CA 91303 USA) was used to sample oral mucosal lesions and later biopsy performed for histopathology. Oral brush cytology samples were fixed in 95% ethanol, cytospined and stained with Pap stain. Data was entered and analyzed using SPSS v 22. The results were presented using tables, charts and disseminated through presentations in conferences and publication in peer reviewed journals.

Results: A total of 47 cytology and histology specimens were taken during the study and all samples were satisfactory for evaluation. The female to male ratio of participants was 1: 1.2 with an age range of 25-79 years and mean of 55 years. The main cytological patterns established at KNH and UoN Dental School Hospital was HSIL and SCC representing 97% of dysplastic and malignant lesions. Histology confirmed dysplasia and malignancy in 28 of 30 cytologically diagnosed cases. There were 2 false positives and 1 false negative cases reported. The sensitivity, specificity, positive predictive value and negative predictive values were 97%, 89%, 93% and 94% respectively with a substantial diagnostic agreement (kappa value) between cytopathology and histopathology of 86% and a p-value of ≤ 0.001.

Conclusion: Brush cytology has been shown to be a reliable cytological technique for screening and early detection of oral mucosal abnormalities as it has a high sensitivity and a substantial diagnostic agreement with histopathology.