Cytokeratin 13 and 17 expressions in oral epithelial dysplasia: correlation with the 5th WHO architectural and cytological features.

Recently, the WHO 5th edition has modified the new architectural and cytological features for the diagnosis of oral epithelial dysplasia (OED). However, the correlation of these histopathological features with malignant transformation (MT) and recurrence (RE) of the lesions remains controversial. There is no study investigated the association between architectural and cytological features of the 5th WHO criteria with a reliable diagnostic marker for MT in OED. Therefore, this study aimed to correlate the 5th edition WHO histopathological diagnostic criteria of OED with the immunohistochemical expression of CK13/CK17, one of reliable diagnostic markers for MT in OED. A total of 32 samples of leukoplakia, erythroplakia, and erythroleukoplakia which histologically proved OED were included in the study. The specimens were graded according to 5th edition WHO criteria and categorized as 15 mild OED and 17 moderate to severe OED. The architectural and cytological features from the 5th WHO diagnostic criteria for OED were collected. The CK13/CK17 immunohistochemistry was performed. The CK13 and CK17 expression was graded semi-quantitatively. The association between architectural and cytological features with CK13/CK17 immunohistochemical expression and with histopathological diagnosis were analyzed. Eight histopathological features: irregular epithelial stratification, reduced keratinocyte cohesion, abnormal variation in nuclear size and shape, abnormal variation in cell size and shape, single cell keratinization and increased nuclear size were significantly correlated with CK13 weak/CK17 strong expression pattern and the diagnosis of moderate to severe OED (p < 0.05). Larger samples are required to enhance the accuracy in the diagnosis and prediction in the OED lesions.