Dysplasia in oral lichen planus: relevance, controversies and challenges. A position paper

Abstract

Background Patients with oral lichen planus (OLP) have an increased risk of oral cancer. For this reason, OLP is classified as an oral potentially malignant disorder. However, the precise personal (or individual) risk is unknown. Recent meta-analytical studies have reported that dysplastic OLP may transform to cancer in around 6% of cases, while the rate of transformation is lower (<1.5%) in non-dysplastic cases. The presence of epithelial dysplasia has emerged as the most powerful indicator for assessing cancer risk in oral potentially malignant disorders in routine practice. However, the general acceptance of epithelial dysplasia as an accompanying histologic feature in OLP is subject to great controversy. Many pathologists consider the presence of dysplasia as a criterion to exclude OLP when routinely reporting on this disease. This practice, widespread among oral pathology professionals, has resulted in the underestimation of the potential for malignancy of OLP. Material and Methods A review of the literature was carried out in order to critically analyze the relevance, controversies and challenges encountered across the diagnosis of epithelial dysplasia in OLP. Results 12 studies have been published examining dysplastic changes in OLP, reporting Figures ranging from 0.54% to 25% of cases with dysplasia in the first diagnostic biopsy. The diagnosis of dysplasia in the OLP poses an additional difficulty due to the fact that the affected oral epithelium per se develops changes related to autoimmune aggression. Among the most frequent histological features of OLP that develops dysplasia are basal cell hyperplasia with basaloid appearance, loss of basal cells polarity, cellular and nuclear pleomorphism and irregular stratification. Conclusions Epithelial dysplasia should not be considered an exclusion criterion for OLP; its evaluation requires experienced pathologists in this field. Key words: Oral lichen planus, epithelial dysplasia, oral cancer.

Langerhans Cells, T Cells, and B Cells in Oral Lichen Planus and Oral Leukoplakia

“…In this study, we chose to include LPL patients with a histopathological diagnosis of benign hyperkeratosis and without dysplasia. Dysplasia can be present in LPL but is a rare finding in OLP [ 32 ]. Dysplasia may affect the T cell profile in the inflammatory infiltrate [ 3 ].…”

Significance of immunohistochemistry biomarkers in prediction of malignant transformation of oral lichen planus: A systematic review

“…Currently, the absence or presence of epithelial dysplasia is the gold standard for assessment of the risk of MT in OLP ( 7 ). However, this standard is still a challenging because it lacks the intra-/inter-observer reproducibility even with a new binary system of grading OED ( 38 ) and development of cancer in OLP lesions without epithelial dysplasia has also been reported.…”

“…The MTR varies among different clinical types but generally higher in atrophic and/or erosive types. Currently, the absence or presence of oral epithelial dysplasia (OED) is still the mainstay for malignant transformation (MT) risk assessment ( 7 ). However, histopathological observations do not provide a clear distinction between dysplasia developed in OLP and lichenoid reaction developed in oral dysplasia and are also subject to inter and intra-observer variability ( 8 ).…”

“…Additionally, presence of epithelial dysplasia and its grade is not a reliable indicator of the biological behavior of these lesions. A recent meta-analysis showed that 6% of dysplastic OLP progressed to carcinoma, but also that less than 1.5 % of non-dysplastic lesions progressed to oral cancer ( 7 ). Since this is prognostically important, there is an urgent need for novel biomarkers that can accurately predict the malignant potential of OLP lesions.…”

Risk of Malignant Transformation in 3173 Subjects with Histopathologically Confirmed Oral Lichen Planus: A 33-Year Cohort Study in Northern Italy

“…The use of immunosuppressants has been regarded as a possible risk factor of malignant transformation, but it is unclear if this could be related to the suppression of the immune response or because of the decreasing local inflammatory reaction [20][21][22]. Moreover, topical corticosteroid, the gold-standard treatment for the last 20 years, could influence the time of cancer development [23,24].…”