Liquid-based oral brush cytology in the diagnosis of oral leukoplakia using a modified Bethesda Cytology system

Abstract

Objectives: This study aimed to develop diagnostic criteria to identify oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMDs) using oral liquid-based brush cytology (OLBC), and to compare its accuracy with the gold standard of surgical biopsy and histopathological diagnosis of oral leukoplakia.

Methods: A total number of 134 samples were collected. All patients underwent Orcellex® brush biopsy with liquid-based cytology immediately prior to diagnostic surgical biopsy. A preliminary study was first performed utilizing samples from 4 distinct lesion groups (20 samples) to revise the 2014 Bethesda Cytology system for use with OLBC specimens.

Results: Five diagnostic groups of OLBC for the diagnosis of OSCC and OPMDs with relevant cytopathological features were established. From the 114 samples in the test group, 101 were included. The other 13 were excluded due to inadequate cellularity. The test showed sensitivity, specificity, positive predictive value and negative predictive value of 75%, 76%, 76% and 75%, respectively, and an accuracy of 75%. The use of the oral brush sampling technique was well accepted by multiple clinicians; however, local anaesthetic was suggested to be useful prior to performing the brush biopsy.

Conclusions: Oral liquid-based brush cytology using the Orcellex® brush and ThinPrep® system is a simple and minimally invasive procedure for adequate intraepithelial sampling and can be used as an adjunct for the early detection of oral cancer. The modified Bethesda system established useful means for OLBC assessment that can be utilized in future studies to increase the standardization of oral cytology assessment.

Keywords: brush biopsy; diagnosis; liquid-based cytology; oral; oral leukoplakia.