Non-computer-assisted liquid-based cytology for diagnosis of oral squamous cell carcinoma

The development of oral squamous cell carcinoma (OSCC) occasionally follows the neoplastic progression of other premalignant lesions. Although biopsy is the definitive diagnostic method, liquid-based cytology is an adequate method for screening suspicious lesions. We compared liquid-based cytology to histology for diagnosis of OSCC in patients with oral lesions that raised clinical suspicion of malignancy. Our sample consisted of 48 patients. Cytological samples were obtained by scraping the lesion superficially using Cytobrush®. We conducted cytological and histopathological evaluation of all preparations. We estimated sensitivity and specificity levels as well as positive and negative predictive values. The degree of inter-observer agreement for both methods was assessed using the kappa index. Twenty-eight (58.3%) of the cases finally were diagnosed with OSCC and 20 (41.7%) were determined to be premalignant lesions. We observed eight false negatives and no false positives; OSCC prevalence was 56.5%. The values for diagnostic indices were: sensitivity, 69% (CI 95%, prevalence 51.87); specificity, 100%; positive predictive value, 100%; negative predictive value, 71% (CI 95% 54.82). A kappa index of 0.622 (CI 95% 0.93, 0.39) was observed.