Oral leukoplakia classification and staging system with incorporation of differentiated dysplasia.

OBJECTIVES: A classification and staging system for oral leukoplakia (OL) was introduced to promote uniform reporting. In this system, size and the histopathologic diagnosis are assessed and combined in a staging system. The various stages could be predictive for malignant transformation of OL. Differentiated dysplasia (DD) was recently recognized as an important architectural pattern of dysplasia and is highly associated with malignant transformation (MT) of OL. In the present study, DD was incorporated in the OL-system. The aim of the present study was to test the adapted system on a cohort of patients with OL. PATIENT AND METHODS: The group consisted of 140 patients. The size, absence or presence and degree of classic dysplasia (CD) and DD were incorporated into the OL-system. RESULTS: In 31/140 patients, MT occurred. Size was not statistically significant with MT (p = 0.422). The presence of dysplasia was predictive for MT (p = 0.003), whereby severe CD and DD were highly statistically significant for MT (p = 0.008). Stage IV was statistically significant for MT (p = 0.011). CONCLUSIONS: The present study emphasizes the value of the slightly modified OL-system with incorporation of DD in uniform reporting of OL and the value in predicting MT.