Which of the following pre-malignant condition is associated with the highest probability of progression to malignancy?

Erythroplakia is a potentially malignant disorder, almost all lesions contain dysplastic cells and most contain severe dysplasia or are carcinoma in situ or carcinoma. Malignant potential of erythroplakia is 17 times higher than leukoplakia. It presents as a bright red velvety plaque which cannot be characterized clinically or pathologically as any other recognizable condition. Risk factors include tobacco, alcohol and betel. Most common sites are lower alveolar mucosa, gingivobuccal sulcus, and the floor of the mouth. Treatment: Erythroplakia should be excised and the patient should be advised to stop tobacco/alcohol/betel habits. Ref: Oral Medicine and Pathology at a Glance By Crispian Scull, Page 40; Tobacco Effects In The Mouth By Robe E. Mecklenburg, Page 5; The Nature Of Disease: Pathology for The Health Professions By Thomas H. McConnell, Page 94