4. Potentially malignant disorders of the oral and oropharyngeal mucosa

A range of potentially malignant disorders is recognized but erythroplakia (erythroplasia), leukoplakia and lichenoid lesions are the most important. Others, such as actinic cheilitis, discoid lupus erythematosus, submucous fibrosis, Fanconi anaemia (syndrome) and other lesions are important but generally less common (Table 1).

Our inability to be able to define the risk of malignant transformation of a potentially malignant oral lesion for an individual patient is one of the biggest challenges in the field, as is the inability to reliably predict the effects of any treatments. Sadly, the evidence base is missing.

It is even more crucial, therefore, to ensure that the patient gives fully informed consent to the management decided after full discussion with the clinician.

This article focuses on erythroplakia, leukoplakia and lichenoid lesions/lichen planus.

Erythroplakia is rare (<1.0%), typically related to tobacco and alcohol use, and seen in the middle-aged and the older patient. It is usually a solitary lesion defined as a ‘fiery red patch that cannot be characterized clinically or pathologically as any other definable disease’. The clinical appearance is often of a flat or even depressed erythematous area of mucosa and for that reason the term ‘erythroplasia’ may be more appropriate (Figure 1). In some, there is a mixture of red and white changes – when the lesion is termed ‘erythroleukoplakia’ or non-homogeneous leukoplakia.