Accuracy of leukoplakia diagnoses: a retrospective study

The objective of this study was to review the diagnostic accuracy of clinicians identifying leukoplakia and the diagnostic terminology used to indicate leukoplakic lesions at the University of Nebraska Medical Center (UNMC) oral biopsy service. Biopsy archives from the years 1983, 1995, 2005, and 2015 in the UNMC College of Dentistry were reviewed. Cases with a clinical diagnosis of leukoplakia (or white plaque), hyperkeratosis, dysplasia, and/or carcinoma were included in the study. Demographic and clinical information was recorded and descriptive statistics were utilized. Of 6113 cases, 517 lesions (8.46%) from 508 patients met the inclusion criteria. The mean age of the patients was 56.87 years, and the sample included 286 men and 222 women. Of these 517 lesions, 195 (37.72%) were clinically diagnosed as leukoplakia or white plaque. The records revealed that 133 (68.21%) of 195 clinical diagnoses were correct, with lesions histologically exhibiting hyperkeratosis (75 cases), dysplasia (52 cases), or carcinoma (6 cases). The remaining 62 lesions (31.79%) were found to have other histologic diagnoses. Hyperkeratosis made up the largest portion of the correct diagnoses. In general, the ability of clinicians to successfully identify leukoplakia improved over the years (46.15%, 73.68%, 64.29%, and 76.00% in 1983, 1995, 2005, and 2015, respectively). However, clinicians continue to misclassify identifiable pathoses such as lichen planus, lichenoid mucositis, and fibroma as leukoplakia. Hyperkeratosis and dysplasia, both of which represent histologic diagnoses, appear to be popularly misused clinical terms.