Erythroplakia has been defined as a “bright red velvety plaque or patch which cannot be characterized clinically or pathologically as being due to any other condition.”The word is an adaptation of the French term “erythroplasie de Queyrat,”which describes a similar-appearing lesion of the glans penis with a comparable premalignant tendency. Although red lesions of the oral mucosa have been noted for many years, the use of the term “erythroplakia” in this context has been common for only about 25 years.
Erythroplakic lesions are easily overlooked, and the true prevalence of the condition is unknown. Erythroplakia is far less common than leukoplakia in most histopathologic series, but this reflects the fact that leukoplakias are more likely to have biopsies performed on them and emphasizes the lack of appreciation of the clinical significance of erythroplakia since it has been proposed that most erythroplakic lesions are precursors of oral squamous cell carcinoma.A number of studies have shown that the majority of erythroplakias (particularly those located under the tongue, on the floor of the mouth, and on the soft palate and anterior tonsillar pillars) exhibit a high frequency of premalignant and malignant changes.Although the etiology of erythroplakia is uncertain, most cases of erythroplakia are associated with heavy smoking, with or without concomitant alcohol abuse.
Clinical Features Several clinical variants of erythroplakia have been described, but there is no generally accepted classification. Shear
described “homogeneous erythroplakia, erythroplakia interspersed with patches of leukoplakia, and granular or speckled erythroplakia”; most authors consider this last category to be identical to speckled leukoplakia (Figure 5-33). Many of these lesions are irregular in outline, and some contain islands of normal mucosa within areas of erythroplakia, a phenomenon that has been attributed to the coalescence of a number of precancerous foci.
Erythroplakia occurs predominantly in older men, in the sixth and seventh decades of life.
Erythroplakias are more commonly seen on the floor of the mouth, the ventral tongue, the soft palate, and the tonsillar fauces, all prime areas for the development of carcinoma. Multiple lesions may be present. These lesions are commonly described as erythematous plaques with a soft velvety texture. Almost all of the lesions are asymptomatic and therefore unlikely to be drawn to the dentist’s attention by the patient.Histopathologic Features
Different studies have demonstrated that 80 to 90% of cases of erythroplakia are histopathologically severe epithelial dysplasia, carcinoma in situ, or invasive carcinoma. In one study, none of the cases of erythroplakia was histologically found to represent benign keratosis.
Differential DiagnosisIn view of the clinical significance of erythroplakia, its differentiation from other red inflammatory lesions of the oral mucosa is critical. Clinically similar lesions may include ery
thematous candidiasis, areas of mechanical irritation, denture stomatitis, vascular lesions, and a variety of nonspecific inflammatory lesions.Because localized areas of redness are not uncommon in the oral cavity, areas of erythroplakia are likely to be disregarded by the examiner, and they are often falsely determined to be a transient inflammatory response to local irritation. Differentiation of erythroplakia from benign inflammatory lesions of the oral mucosa can be enhanced by the use of a 1% solution of toluidine blue, applied topically with a swab or as an oral rinse. Although this technique was previously found to have limited usefulness in the evaluation of keratotic lesions, prospective studies of the specificity of toluidine blue staining of areas of early carcinoma contained in erythroplakic and mixed leukoplakic-erythroplakic lesions reported excellent results, with false-negative (underdiagnosis) and false-positive (overdiagnosis) rates of well below 10%.
Treatment and Prognosis
The treatment of erythroplakia should follow the same principles outlined for that of leukoplakia (see section on management of leukoplakia, above). Observation for 1 to 2 weeks following the elimination of suspected irritants is acceptable, but prompt biopsy at that time is mandatory for lesions that persist. The toluidine blue vital staining procedure may be redone following the period of elimination of suspected irritants. Lesions that stain on this second application frequently show extensive dysplasia or early carcinoma. Epithelial dysplasia or carcinoma in situ warrants complete removal of the lesion. Actual invasive carcinoma must be treated promptly according to guidelines for the treatment of cancer. Most asymptomatic malignant erythroplakic lesions are small; 84% are ≤ 2 cm in diameter, and 42% are ≤ 1 cm.However, since recurrence and multifocal involvement is common, longterm follow-up is mandatory.
Treatment and Prognosis
The treatment of erythroplakia should follow the same principles outlined for that of leukoplakia (see section on management of leukoplakia, above). Observation for 1 to 2 weeks following the elimination of suspected irritants is acceptable, but prompt biopsy at that time is mandatory for lesions that persist. The toluidine blue vital staining procedure may be redone following the period of elimination of suspected irritants. Lesions that stain on this second application frequently show extensive dysplasia or early carcinoma. Epithelial dysplasia or carcinoma in situ warrants complete removal of the lesion. Actual invasive carcinoma must be treated promptly according to guidelines for the treatment of cancer. Most asymptomatic malignant erythroplakic lesions are small; 84% are ≤ 2 cm in diameter, and 42% are ≤ 1 cm.However, since recurrence and multifocal involvement is common, longterm follow-up is mandatory.