Oral leukoplakia is a predominantly white lesion of the oral mucosa that cannot be characterized as any other definable lesion some oral leukoplakias will transform into cancer (The 2nd International Symposium in Sweden 1994 Department of Oral Pathology, Shandong University 5Department of Oral Pathology, Shandong University 5  Oral leukoplakia is a predominantly white lesion of the oral mucosa that cannot be characterized as any other definable lesion; some oral leukoplakias will transform into cancer. (The 2nd International Symposium in Sweden, 1994 )