A review of the recent literature regarding malignant transformation of oral lichen planus

Case Report: Recalcitrant oral lichen planus involving bilaterally buccal mucosae treated with a combination of photodynamic and photobiomodulation therapies

Background

Managing recalcitrant oral lichen planus (OLP) can be challenging. Laser therapy has been suggested as an alternative to corticosteroids for treatment. Photodynamic therapy (PDT) is a non-invasive technique that enables the removal of lesions without surgery. Photobiomodulation therapy (PBMT) can promote healing and recovery of the lesions.

Case presentation

The objective was to treat unresponsive bilateral OLP of the whole buccal mucosae with a combination of PDT and PBMT.

Results

A 43-year-old Thai male presented with the severe painful reticular type of OLP of bilateral buccal mucosae involving upper and lower vestibular areas. The lesions were not remitted with either prednisolone systemic steroids or fluocinolone topical corticosteroids. After undergoing ten sessions of PDT with 10% 5-Aminolevulinic acid (5-ALA) in the form of thermoplastic gel and a 635 nm diode laser at 100 to 400 mW with an energy density of 20 to 30 J/cm 2 in continuous wave mode, combined with five interim-sessions of PBMT using a 635 nm diode laser at 200 to 300 mW with an energy density of 6 to 10 J/cm 2 in continuous wave, the patient reported relief of burning sensation beside remission of lesions without any complications.

Conclusion

The wide-spreading recalcitrant OLP with burning sensation can be managed by combining PDT and PBMT.

Characteristics of Clinically Classified Oral Lichen Planus in Optical Coherence Tomography: A Descriptive Case-Series Study

Malignant transformation of oral lichen planus (OLP) into oral squamous cell carcinoma is considered as one of the most serious complications of OLP. For the early detection of oral cancer in OLP follow-up, accurate localization of the OLP center is still difficult but often required for confirmatory biopsy with histopathological examination. Optical coherence tomography (OCT) offers the potential for more reliable biopsy sampling in the oral cavity as it is capable of non-invasively imaging the degenerated oral layer structure. In this case-series study with 15 patients, features of clinically classified forms of OLP in OCT cross-sections were registered and correlated with available histologic sections. Besides patients with reticular, atrophic, erosive and plaque-like OLP, two patients with leukoplakia were included for differentiation. The results show that OCT yields information about the epithelial surface, thickness and reflectivity, as well as the identifiability of the basement membrane and the vessel network, which could be used to complement the visual clinical appearance of OLP variants and allow a more accurate localization of the OLP center. This forms the basis for further studies on OCT-assisted non-invasive clinical classification of OLP, with the aim of enabling decision support for biopsy sampling in the future.

Oral Squamous Cell Carcinomas Developing from Oral Lichen Planus: A 5-21 year Retrospective Study

Background and Aims

There is insufficient data regarding clinical characteristics, relapse rates, as well as lymph node metastasis of squamous cell carcinomas of the oral cavity (OSCC) developing from oral lichen planus (OLP-OSCC). The aim of this retrospective study was to evaluate clinical characteristics, as well as relapse, recurrence and survival rates of OLP-OSCC.

Methods

In a retrospective monocenter analysis, all consecutive patients with an OSCC treated in the time period 1st January 2000-December 31 2016 were reviewed. All patients with OSCC developing from OLP/OLL (oral lichenoid lesions) were identified and analyzed for epidemiological data, risk profile, location of primary tumor, pTNM classification, lymph node metastasis, primary therapy, recurrence, and outcome.

Results

A total of 103 patients (45%♂/ 55%♀) with an average age of 62 ± 14 year were included in this study. At the time of initial diagnosis, 17% (n = 18) of patients had cervical metastases (CM) whereas only 11% (11 patients) displayed advanced tumor sizes (T > 2). T-status (p = 0.003) and histopathological grading (p = 0.001) had an impact on the incidence of CM. 39.6% of the patients developed a relapse after an average of 24 months with a mean of two recurrences per patient. Advanced tumor size had a significant impact on the 5 year overall survival and was associated with disease-free survival of the patients (p < 0.001, respectively p = 0.004).

Conclusion

Although initial lymph node metastases were not more frequent, more aggressive recurrence patterns compared to OSCC were seen for OLP-OSCC. Therefore, based on the study results, a modified recall for these patients is suggested.

Oral lichenoid lesion in association with chemotherapy treatment for non-Hodgkin lymphoma or lichen planus? Review of the literature and report of two challenging cases

Background

The diagnosis of oral lichenoid lesions (OLL) remains a challenge for clinicians and pathologists. Although, in many cases, OLL cannot be clinically and histopathologically distinguishable from oral lichen planus (OLP), one important difference between these lesions is that OLL has an identifiable etiological factor, e.g. medication, restorative material, and food allergy. The list of drugs that can cause OLL is extensive and includes anti-inflammatory drugs, anticonvulsants, antihypertensives, antivirals, antibiotics, chemotherapeutics, among others. This work aimed to perform a literature review of OLL related to chemotherapy drugs and to report two cases of possible OLL in patients with B-cell and T-cell non-Hodgkin lymphomas in use of chemotherapy and adjuvant medications. We also discuss the challenge to clinically and histopathologically differentiate OLL and OLP.

Case presentation

In both cases, oral lesions presented reticular, atrophic, erosive/ulcerated, and plaque patterns. The diagnosis of OLL was initially established in both cases by the association of histopathology and history of onset of lesions after the use of medications. Although the patients have presented a significant improvement in the oral clinical picture for more than 2 years of follow-up, they still have some lesions.

Conclusion

A well-detailed anamnesis associated with the drug history, temporal relationship of the appearance of the lesions, and follow-up of patients are fundamental for the diagnosis of OLL related to drugs. Nevertheless, its differentiation from OLP is still a challenge.

What is the malignant transformation potential of oral lichen planus?

Data sources In this systematic review and meta-analysis, Medline, Scopus and Web of Science databases were searched using Medical Subject Headings (MeSH) to identify studies assessing the risk of malignant transformation in oral lichen planus (OLP).Study selection Observational studies published in English between 2003-2020 were independently assessed for inclusion by two blinded investigators.Data extraction and synthesis Data were extracted independently by two investigators followed by discussion to reach consensus. This included: study design and patient characteristics; length of follow-up; risk of bias; method of OLP diagnosis; oral squamous cell carcinoma (OSCC) risk factors; rate of malignant transformation; and individual characteristics of malignant transformation cases. Cases of malignant transformation in the included studies were only included in meta-analysis if: 1) OLP diagnosis met current diagnostic criteria; 2) OSCC developed in the same site as previously diagnosed OLP after at least six months' follow-up; 3) the patient had no history of systemic immunosuppressive therapy, head and neck malignancy, or organ transplantation. Risk of bias was assessed using the modified Newcastle-Ottawa scale, and meta-analysis was conducted to estimate overall risk of OLP malignant transformation using the DerSimonian and Laird method. Pooled univariate odds ratios (OR) for malignant transformation were calculated based on gender, smoking status, alcohol consumption, hepatitis C infection and OLP subtype.Results In total, 593 studies were identified after removal of duplicates and 33 studies were included for data extraction. The included sample comprised 12,838 patients with OLP, and 151 malignant transformation cases were reported in the included studies. The authors excluded 56 malignant transformation cases from the meta-analysis, most commonly because of the absence of pathological OLP diagnosis. Among included malignant transformation cases, the mean (SD) age was 58.1 (12.4) years, and 64% of the sample was female. Random-effects meta-analysis estimated an OLP malignant transformation rate of 0.2% (95%CI: 0.1-0.3%). Heterogeneity was low (I2 = 28.74%, p = 0.065). Malignant transformation was significantly higher among smokers (OR = 4.62, p = 0.001), alcohol consumers (OR = 3.22, p = 0.05), those with hepatitis C (OR = 3.77, p = 0.03) and atrophic or erosive OLP subtypes (OR = 2.70, p = 0.03). Gender was not associated with increased risk of malignant transformation.Conclusions The malignant transformation rate of OLP is likely to be lower than previously reported, possibly as a result of variable diagnostic criteria. Whilst encouraging, clinical vigilance remains necessary, as OLP does carry a small risk of malignant transformation. Smoking, alcohol use, hepatitis C infection and erosive or atrophic subtypes appear to have a greater rate of malignant transformation.

Elevation of Serum SSCCAII in Cutaneous and Oral Lichen Planus: Missing Link for Hidden Carcinogenic Potential?

Context:

Lichen planus (LP) is an immune mediated inflammatory condition. SCCAII is a useful biomarker reflecting Th17 type inflammation. It is also a tumour marker, especially for Squamous cell carcinoma (SCC) Mechanism of carcinogenesis in LP is still unknown. Chronic inflammation may facilitate the development of cellular clones in the epidermis.

Aims:

Estimation of serum level of SCCA II in patients with cutaneous and oral LP (OLP) to detect its role in LP pathogenesis, and to reveal the missing link in understanding mechanism of carcinogenesis in LP.

Methods and Material:

A case control study, where 100 subjects were included; 80 LP patients (40 cutaneous & 40 oral) and 20 apparently healthy controls. We obtained an informed written consent from each subject prior the participation. Cutaneous and oral LP were diagnosed clinically, SCCA II level was measured by ELISA technique.

Statistical analysis used:

Statistical analysis was done using SPSS vs.25. (IBM, Armonk, New York, United states). Numerical data was summarized as means and standard deviations or medians and ranges.

Results:

Median SSCCAII level was significantly higher in LP cases compared to controls (P < 0.001) and was significantly higher in patients with OLP compared to patients with cutaneous LP (P ≤ 0.001). Post hoc analysis revealed that median SSCCAII was significantly higher in patients with ulcerative type compared to both reticular type and others. It was also significantly higher in patients with actinic type compared to both hypertrophic type and classic type. Median SSCCAII was significantly higher in patients with ulcerative OLP compared to actinic LP (P < 0.001).

Conclusions:

Our study revealed that serum SCCAII level was higher in patients with cutaneous and OLP. This might be linked to the pathogenesis of LP, especially actinic and erosive OLP. SCCAII level could facilitate the screening and early detection of patients at risk, a potential alarm to launch accurate assessment and continue follow up of cutaneous as well as O LP patients.

A machine-learning algorithm for the reliable identification of oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a relatively common oral disorder which shares clinical and histopathological features with other lichenoid lesions, leading to considerable inter-observer disagreement. This negatively impacts understanding of the pathogenesis and malignant transformation potential of this condition.

METHODS

Artificial intelligence was employed to create a machine-learning artificial neural network to identify and quantify mononuclear cells and granulocytes within the inflammatory infiltrates in digitized hematoxylin and eosin microscopic slides. Twenty-four regions of interest were extracted from OLP cases for learning purposes and validated on a retrospective cohort of 130 cases. All cases were related to patients with confirmed diagnoses of OLP, oral lichenoid lesions (OLLs), or oral epithelial dysplasia (OED) with lichenoid host response.

RESULTS

The number of inflammatory cells was statistically significantly higher in OLP compared to OLLs or OED with lichenoid host response (p < 0.0005). The proposed machine-learning method was reliably capable of detecting OLP cases based on the number of inflammatory cells and the number of mononuclear cells with an area under the curve of 0.982 and 0.988, respectively. Identifying a cut-off point between OLP and other lichenoid conditions based on the number of mononuclear cells showed a sensitivity of 100% and an accuracy of 94.62%.

CONCLUSION

Artificial intelligence has shown promising outcomes and provides a robust approach to enhance the accuracy of anatomical pathologists in accurately diagnosing OLP using features of disease pathogenesis.

Horoscopic role of CD105 (Endoglin) in progression of oral lichen planus: An immunohistochemical study

Context

Role of CD105(Endoglin) in Pathogenesis and progression of OLP.

Aim

To assess the role of neoangiogenesis in the progression of OLP by determining the expression of CD105 in OLP and normal mucosa.

Settings and Design

The present study includes a total of 70 formalin-fixed paraffin-embedded blocks of which the study group comprises 50 tissue sections histopathologically confirmed as OLP. They were subdivided into two groups - Group I (Reticular OLP) and Group II (Erosive OLP) - 25 each. The control group (designated as Group III) included 20 sections of normal mucosa.

Materials and Methods

All the sections were 4 μm thick and stained with CD105 antibodies. After identifying areas of highest vascularity (hot spots) in low power (×10) magnification, individual microvessels were counted manually at high power (×40) magnification.

Statistical Analysis Used

Analysis of variance test was used to determine the difference of microvessel density (MVD) between variants of OLP and normal mucosa and Cohen's kappa statistic was used to check interobserver variability.

Results

CD105 staining showed a mean MVD of 1.31 ± 1.8 in the normal mucosa compared to 1.68 ± 1.4 and 4.14 ± 2.7 in the reticular and erosive variants, respectively, with a P = 0.000*, which is statistically significant (*P < 0.05 is statistically significant).

Conclusion

Based on our observations, it is evident that compared to normal mucosa, MVD is greater in lichen planus. Within the two variants of OLP, MVD is higher in Erosive variant compared with Reticular variant, foreshadowing the role of neoangiogenesis in the progression of OLP and its possible malignant transformation.

Oral potentially malignant disorders: A consensus report from an international seminar on nomenclature and classification, convened by the WHO Collaborating Centre for Oral Cancer

Oral potentially malignant disorders (OPMDs) are associated with an increased risk of occurrence of cancers of the lip or oral cavity. This paper presents an updated report on the nomenclature and the classification of OPMDs, based predominantly on their clinical features, following discussions by an expert group at a workshop held by the World Health Organization (WHO) Collaborating Centre for Oral Cancer in the UK. The first workshop held in London in 2005 considered a wide spectrum of disorders under the term "potentially malignant disorders of the oral mucosa" (PMD) (now referred to as oral potentially malignant disorders: OPMD) including leukoplakia, erythroplakia, proliferative verrucous leukoplakia, oral lichen planus, oral submucous fibrosis, palatal lesions in reverse smokers, lupus erythematosus, epidermolysis bullosa, and dyskeratosis congenita. Any new evidence published in the intervening period was considered to make essential changes to the 2007 classification. In the current update, most entities were retained with minor changes to their definition. There is sufficient evidence for an increased risk of oral cancer among patients diagnosed with "oral lichenoid lesions" and among those diagnosed with oral manifestations of 'chronic graft-versus-host disease'. These have now been added to the list of OPMDs. There is, to date, insufficient evidence concerning the malignant potential of chronic hyperplastic candidosis and of oral exophytic verrucous hyperplasia to consider these conditions as OPMDs. Furthermore, due to lack of clear evidence of an OPMD in epidermolysis bullosa this was moved to the category with limited evidence. We recommend the establishment of a global research consortium to further study the natural history of OPMDs based on the classification and nomenclature proposed here. This will require multi-center longitudinal studies with uniform diagnostic criteria to improve the identification and cancer risk stratification of patients with OPMDs, link them to evidence-based interventions, with a goal to facilitate the prevention and management of lip and oral cavity cancer.

Cancerous lesions in the vicinity of dental implants: a systematic review

Introduction: The massive diffusion of dental implant treatments in the last decades leads to the appearance of complications, most of them inflammatory, although important complications have been described as malignant lesions in the vicinity of dental implants. The objective of this article is to describe the cases described in the literature of oral squamous cell carcinoma (OSCC) or clinical variants and metastases, in the vicinity of dental implants and to analyze the possible etiological agents involved. Material and methods: The criteria used were those described in the PRISMA® Declaration for performing systematic reviews. An electronic search was performed on MEDLINE (via PubMed) using the terms MeSH: “dental implants” AND “squamous cell carcinoma” OR “dental implant complications” AND “squamous cell carcinoma”. Results: Thirty-eight articles describing a total of 76 cases of OSCC or clinical variants, as well as metastasis in the vicinity of dental implants, were included. Conclusions: It is not possible to establish a cause-effect relationship between dental implants and the development of OSCC. Its clinical appearance can be confused with periimplantitis, so that, in cases of sudden onset, which do not respond to conventional treatment and/or have associated alterations in sensitivity, a biopsy should be performed.

Keratin 17-positive Civatte bodies in oral lichen planus-distribution variety, diagnostic significance and histopathogenesis

Although emergence of keratin 17 (K17) and reciprocal loss of K13 are immunohistochemical hallmarks for oral mucosal malignancy, we report here findings of K17-positive (+) speckles, possibly equivalent to Civatte bodies, in benign oral lichen planus. Sixty-two biopsy samples from oral lichen planus cases were subjected to immunohistochemical examinations to analyze the distribution as well as histopathogenesis of Civatte bodies. K17 was irregularly positive among oral lichen planus-affected epithelial cells, and K17-positive (+) filamentous structures were irregularly distributed within the cytoplasm in confocal images. K17+ speckles were identified as Civatte bodies, and they were mainly distributed in the interface between epithelial cells and lymphocytic infiltrates (type A, 52.8%), followed by distribution within the epithelial layer (type B, 24.7%) or within the lamina propria with lymphocytic infiltration (type C, 22.5%). Apoptotic figures were often engulfed by macrophages and clearly distinguished from Civatte bodies by the presence TUNEL signals. These results indicate that K17 is a sensitive immunohistochemical marker for Civatte bodies and useful for differential diagnosis of oral lichen planus from other oral mucosal lesions. Civatte bodies are generated from denucleation of K17+ epithelial cells during the process of cell death via dyskeratosis, which is possibly related to blood capillary collapse.

Discrimination of oral squamous cell carcinoma from oral lichen planus by salivary metabolomics

OBJECTIVE

This study was conducted to distinguish salivary metabolites in oral squamous cell carcinoma (OSCC) from those in oral lichen planus (OLP) to identify practical biomarkers for the discrimination of OSCC from OLP.

SUBJECTS AND METHODS

Whole unstimulated saliva samples were collected from patients with OSCC (n = 34) and OLP (n = 26). Hydrophilic metabolites in the saliva samples were comprehensively analysed by capillary electrophoresis mass spectrometry. To evaluate the discrimination ability of a combination of multiple markers, a multiple logistic regression (MLR) model was developed to differentiate OSCC from OLP.

RESULTS

Fourteen metabolites were found to be significantly different between the OSCC and OLP groups. Among them, indole-3-acetate and ethanolamine phosphate were used to develop the MLR model. The combination of these two metabolites showed a high area under the receiver operating characteristic curve (0.856, 95% confidential interval: 0.762-0.950; p < .001) for discriminating OSCC from OLP.

CONCLUSIONS

We identified salivary metabolites for discerning between OSCC and OLP, which is clinically important for detecting the malignant transformation of OLP by both dentists and oral surgery specialists. Our candidate salivary metabolites show potential for non-invasive screening of OSCC versus OLP.

Mucocutaneous Diseases

Mucocutaneous diseases affecting the oral cavity are predominantly immune mediated or inflammatory. Three of the most common and clinically significant conditions are reviewed in this article: lichen planus, pemphigus vulgaris, and mucous membrane pemphigoid. Because oral manifestations may be the first or only manifestation of mucocutaneous diseases, oral health professionals play a critical role in the early diagnosis and multidisciplinary management of these conditions.

Lichen planus of lip - Report of a rare case with review of literature

Lichen planus (LP) is a potentially malignant disorder with an immune-mediated etiopathogenesis. The condition frequently affects the skin, oral mucosa, skin appendages, and other mucous membranes. Oral lesions usually precede the onset of skin lesions and in majority of cases may only be presenting symptom. Isolated LP of the lip is rarely encountered in the clinical practice and is usually seen along with skin/other mucous membrane involvement. The clinical appearance poses diagnostic dilemmas and is often misinterpreted. This case report aims to highlight an interesting case of LP of the lower lip in a 50-year-old male patient. The patient presented with a diffuse erosive lesion on the lower lip bordered by white radiating striae on its inner aspect. Histopathological and immunofluorescent studies confirmed LP of the lip. Topical corticosteroids and Vaseline lip therapy were prescribed to the patient. There was considerable healing in the lip lesion during the follow-up period. However, recurrence was noted in the left buccal mucosa.

Increased expression of p16 in both oral and genital lichen planus

Background

Lichen Planus, LP, is an inflammatory disease of possible autoimmune origin affecting mainly oral and genital mucosa and skin. According to the WHO oral LP is considered a potentially malignant disorders. The p16 tumour suppressor protein can act as an inhibitor of cyclin dependent kinases 4 and 6 and thus down regulate cell cycle progression. Since the discovery of p16 several studies have evaluated its expression in various forms of human cancers. The aim of this study was to evaluate and compare the expression of p16 in oral and genital LP and corresponding healthy mucosa.

Material and Methods

A total of 76 cases of oral LP (OLP), 34 cases of genital LP (GLP), 12 cases of healthy oral and 9 cases of healthy genital mucosa were analysed by the use of immunohistochemistry.

Results

Data showed p16 to be highly expressed in both oral and genital LP, higher than in oral (p=0.000), and genital controls (p=0.002).

Conclusions

Results suggest that the over-expression of p16 seen in LP play a part in the histopathology of the disease.

Key words:p16, inflammation, oral, genital, lichen planus, malignant risk.

Rate of malignant transformation of oral lichen planus: A systematic review

OBJECTIVE

The aim of this study was to systematically review the literature to determine: (a) the malignant transformation rate (TR) of oral lichen planus (OLP) and its risk factors; (b) whether or not oral lichenoid lesions (OLL) have a different malignant TR.

MATERIALS AND METHODS

PubMed, Scopus, and Web of Science were used as search engines: only observational, full-length, English language studies were investigated. PRISMA protocol was used to evaluate and present results. PROSPERO registration code is CRD42016048529.

RESULTS

Among 7,429 records screened, only 21 were included in this review. Ninety-two of 6,559 patients developed oral squamous cell carcinoma, with an overall TR of 1.40% (1.37% for OLP and 2.43% for OLL), an annual TR of 0.20%. Female gender, red clinical forms, and tongue site seem to slightly increase the transformation risk.

CONCLUSIONS

This systematic review confirms that both OLP and OLL, the latter with a slightly higher TR, may be considered potentially malignant disorders and suggest that erosive type, female gender and tongue site should be considered as risk factors for OLP transformation. Major efforts should be done to establish strict clinical and histological criteria to diagnose OLP and to perform sounder methodological observational studies.

Association between oral lichen planus and Epstein-Barr virus in Iranian patients

Background

Oral lichen planus (OLP) is a common mucocutaneous disease with malignant transformation potential. Several etiologies such as humoral, autoimmunity, and viral infections might play a role, but still there is no definite etiology for this disease. The aim of this study was to investigate the presence of Epstein-Barr virus (EBV) genome in Iranian patients with OLP as compared to people with normal mucosa.

Materials and Methods

The study was carried out on a case group including 38 tissue specimens of patients with histopathological confirmation of OLP and a control group including 38 samples of healthy mucosa. All samples were examined by nested polymerase chain reaction (PCR) method to determine the DNA of EBV.

Results

Twenty-two (57.9%) female samples and 16 (42.1%) male samples with OLP were randomly selected as the case group, and 20 (52.6%) female samples and 18 (47.4%) male samples with healthy mucosa as the control group. There was a statistically significant difference in the percentage of EBV positivity between the case (15.8%) and the control groups (P < 0.05); in the case group, three female samples (13.6%) and three male samples (18.8%) were infected with EBV; the difference between the genders was not statistically significant (P = 0.50).

Conclusion

Results emphasized that EBV genome was significantly higher among Iranian patients with OLP so antiviral therapy might be helpful.

Malignant transformation of oral lichen planus and oral lichenoid lesions: A meta-analysis of 20095 patient data

OBJECTIVES

For over a century, a heated debate existed over the possibility of malignant transformation of oral lichen planus (OLP). We performed this meta-analysis to evaluate the malignant potential of OLP and oral lichenoid lesions (OLL) and investigate the possible risk factors for OLP malignant transformation into oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

We searched Medline, Scopus, and Web of Knowledge for relevant observational studies. Data on OLP malignant transformation were calculated as a pooled proportion (PP), using the Der-Simonian Liard method. We performed subgroup analyses by OLP diagnostic criteria, site, and clinical type, using Open Meta[Analyst] software. Data on possible risk factors for malignant transformation were pooled as odds ratios (ORs), using Comprehensive Meta-Analysis software.

RESULTS

Pooling data for OLP malignant transformation from 57 studies (19,676 patients) resulted in an overall PP of 1.1% [95% CI: 0.9%, 1.4%], while pooling data from 14 recent studies that used the World Health Organization-2003 diagnostic criteria resulted in an overall-PP of 0.9% [95% CI: 0.5%, 1.3%]. The risk of malignant transformation was higher (PP=2.5%, 95% CI [1%, 4%]) in OLL patients (419 patients). A significant increase of malignant transformation risk was noted among smokers (OR=2, 95% CI [1.25, 3.22]), alcoholics (OR=3.52, 95% CI [1.54, 8.03]), and HCV-infected patients (OR=5, 95% CI [1.56, 16.07]), compared to patients without these risk factors.

CONCLUSION

A small subset of OLP patients (1.1%) develop OSCC; therefore, regular follow-up for these patients is recommended. A higher incidence of malignant transformation was found among smokers, alcoholics, and HCV-infected patients; however, these associations should be further investigated.

Identification of potential therapeutic target genes, key miRNAs and mechanisms in oral lichen planus by bioinformatics analysis

The study aimed to identify the potential target genes and key miRNAs as well as to explore the underlying mechanisms in the pathogenesis of oral lichen planus (OLP) by bioinformatics analysis. The microarray data of GSE38617 were downloaded from Gene Expression Omnibus (GEO) database. A total of 7 OLP and 7 normal samples were used to identify the differentially expressed genes (DEGs) and miRNAs. The DEGs were then performed functional enrichment analyses. Furthermore, DEG-miRNA network and miRNA-function network were constructed by Cytoscape software. Total 1758 DEGs (598 up- and 1160 down-regulated genes) and 40 miRNAs (17 up- and 23 down-regulated miRNAs) were selected. The up-regulated genes were related to nuclear factor-Kappa B (NF-κB) signaling pathway, while down-regulated genes were mainly enriched in the function of ribosome. Tumor necrosis factor (TNF), caspase recruitment domain family, member 11 (CARD11) and mitochondrial ribosomal protein (MRP) genes were identified in these functions. In addition, miR-302 was a hub node in DEG-miRNA network and regulated cyclin D1 (CCND1). MiR-548a-2 was the key miRNA in miRNA-function network by regulating multiple functions including ribosomal function. The NF-κB signaling pathway and ribosome function may be the pathogenic mechanisms of OLP. The genes such as TNF, CARD11, MRP genes and CCND1 may be potential therapeutic target genes in OLP. MiR-548a-2 and miR-302 may play important roles in OLP development.

Oral lichenoid lesions: distinguishing the benign from the deadly

Oral lichen planus is a chronic inflammatory disease of unknown etiology or pathogenesis with varied disease severity that waxes and wanes over a long period of time. Although a common oral mucosal disease, accurate diagnosis is often challenging due to the overlapping clinical and histopathological features of oral lichen planus and other mucosal diseases. Other immune-mediated mucocutaneous diseases can exhibit lichenoid features including mucous membrane pemphigoid, chronic graft-versus-host disease, and discoid lupus erythematosus. Reactive changes to dental materials or to systemic medications can mimic oral lichen planus both clinically and histologically. In these situations the clinical presentation can be useful, as oral lichen planus presents as a multifocal process and is usually symmetrical and bilateral. Dysplasia of the oral cavity can exhibit a lichenoid histology, which may mask the potentially premalignant features. Proliferative verrucous leukoplakia, an unusual clinical disease, can often mimic oral lichen planus clinically, requiring careful correlation of the clinical and pathologic features.

Beta-catenin in disease

In continuation with the previous review on “β-catenin in health”, in this review we discuss the role of β-catenin in the pathogenesis of common oral lesions in the oral and maxillofacial region- oral potentially malignant disorders, their progression to oral squamous cell carcinoma, salivary gland tumors and odontogenic tumours. This review is based on a pubmed search of all the lesions included in the review.

Evaluation of Potential Risk Factors that contribute to Malignant Transformation of Oral Lichen Planus: A Literature Review

AIM

Many studies have suggested that a lesion originally diagnosed as oral lichen planus (OLP) has different possibilities of undergoing malignant transformation in time, although these findings remain a controversial issue; for example, some studies reported different values of potential malignancy of OLP.

INTRODUCTION

World Health Organization (WHO) classifies OLP as a "potentially malignant disorder" with unspecified malignant transformation risk, and suggests that OLP patients should be closely monitored. Numerous studies have attempted to confirm the malignant transformation potential of OLP.

REVIEW RESULTS

The Cochrane Controlled Trials Register, Medline and EMBASE databases, PubMed, Google Scholar, Ovid, Up To Date, BMJ Clinical Evidence, MD Consult, and Science Direct were searched for papers published between 1997 and 2015. The medical subject heading search terms were "lichen planus," "oral lichen planus," "erosive oral lichen planus," "dysplasia," "oral precancerous condition," "oral premalignant condition," oral cancer, oral squamous cell carcinoma (OSCC), and atrophic lichen planus. A total of 120 English language abstracts were reviewed, and 50 relevant articles identified. Because of the extensive literature on the association between OLP and SCC, we have divided the data into genetic and non-genetic factors for more accurate assessment.

CONCLUSION

In this evidence base, malignant transformation ranges from 0 to 37% with a mean of 4.59%. The highest rate of malignancy was noted in erythematosus and erosive lesions. In this way, follow-up of OLP patients could be carried out more efficiently and appropriately.

CLINICAL SIGNIFICANCE

Oral lichen planus is a premalignant lesion. All types of OLP in any site of oral mucosa must be monitored regularly.

Diagnosis of oral lichen planus: a position paper of the American Academy of Oral and Maxillofacial Pathology

Despite being one of the most common oral mucosal diseases and recognized as early as 1866, oral lichen planus (OLP) is still a disease without a clear etiology or pathogenesis, and with uncertain premalignant potential. More research is urgently needed; however, the research material must be based on an accurate diagnosis. Accurate identification of OLP is often challenging, mandating inclusion of clinico-pathological correlation in the diagnostic process. This article summarizes current knowledge regarding OLP, discusses the challenges of making an accurate diagnosis, and proposes a new set of diagnostic criteria upon which to base future research studies. A checklist is also recommended for clinicians to provide specific information to pathologists when submitting biopsy material. The diagnostic process of OLP requires continued clinical follow-up after initial biopsy, because OLP mimics can manifest, necessitating an additional biopsy for direct immunofluorescence study and/or histopathological evaluation in order to reach a final diagnosis.

Oral lichen planus: a literature review and update

Lichen planus (LP) is a common chronic inflammatory condition that can affect skin and mucous membranes, including the oral mucosa. Because of the anatomic, physiologic and functional peculiarities of the oral cavity, the oral variant of LP (OLP) requires specific evaluations in terms of diagnosis and management. In this comprehensive review, we discuss the current developments in the understanding of the etiopathogenesis, clinical-pathologic presentation, and treatment of OLP, and provide follow-up recommendations informed by recent data on the malignant potential of the disease as well as health economics evaluations.

Etiology and pathogenesis of oral lichen planus: an overview

Oral lichen planus is a noninfectious, chronic inflammatory condition that involves the oral mucosal stratified squamous epithelium and the underlying lamina propria and may be accompanied by skin lesions. This overview describes the current understanding of the immunopathologic mechanisms implicated in oral lichen planus.

Oral lichen planus

Lichen planus is an inflammatory mucocutaneous disease that can affect the skin, hair, nails, and mucosal surfaces. Mucosal sites of involvement include oral, genital, ocular, otic, esophageal, and, less commonly, bladder, nasal, laryngeal, and anal surfaces. Oral lichen planus is a mucosal variant of lichen planus, which tends to affect women more often than men, with a typically more chronic course and potential for significant morbidity. Treatment can be challenging, and there is potentially a low risk of malignant transformation; however, therapeutic benefits can be obtained with various topical and systemic medications. Clinical monitoring is recommended to ensure symptomatic control. Increasing awareness and recognition of this entity have continued to fuel advances in therapy and in our understanding of the disease.

A clinical study on oral lichen planus with special emphasis on hyperpigmentation

BACKGROUND

Oral lichen planus (OLP) is a unique disorder affecting generally the older age group. Numerous studies have been done on various aspects of OLP such as pathogenesis, rate of malignant transformation, etc. However, very few studies are available with respect to clinical features especially association of hyperpigmentation and OLP. This study aims at studying the clinical aspects of OLP and study the association between hyperpigmentation and OLP in a south Indian population.

MATERIALS AND METHODS

A total of 58 patients with OLP who attended the outpatient department of our institution were included in the study and a complete history, followed by thorough intraoral examination was done. All the data were recorded and assessed for statistical analysis using SPSS software.

RESULTS

We found that the male to female ratio affected with OLP was 1:1 and the most common form of OLP that was seen was the reticular subtype. Also, buccal mucosa was the most common affected site and more than 60% patients had hyperpigmentation associated with the site affected by OLP. We found a statistically significant relation between the reticular type of OLP and the older age group (51-70 years) with hyperpigmentation.

CONCLUSION

Although further studies are required to say anything conclusively, post-inflammatory changes occurring the mucosa due to OLP could be a cause for hyperpigmentation in the sites affected.

Oral lichen planus: study of 21 cases

BACKGROUND:

Lichen planus is considered to be the most common dermatological disease involving the oral mucosa.

OBJECTIVE:

To investigate the profile, clinical features, and the presence of dysplasia and candidiasis in patients with oral lichen planus.

METHODS:

A total of 21 patients were selected from 258 patients at risk for oral cancer development.

RESULTS:

Most of the patients were white (76,2%), female (66,6%), with mean age of 58.8 years. Eight were smokers and seven were alcohol consumers. The buccal mucosa was the most affected site, followed by the tongue and the gingiva. The reticular pattern was the most common appearance. Histopathology depicted dysplasia in nine cases and cytopathology was positive for Candida in eight cases in the first appointment.

CONCLUSION:

Our data are similar to the literature. Cytopathology was important for the diagnosis of candidiasis. Although the presence of dysplasia was verified, further studies are necessary to clarify the importance of this finding.

Evaluation of ploidy status using DNA-image cytometry of exfoliated mucosal cells in oral lichen planus

Background:

Oral lichen planus (OLP) is one of the potentially malignant disorders (PMDs) with a malignancy rate of 0.2-2%. Aneuploidy is considered to be one of the important markers for malignant transformation and DNA-image cytometry (DIC) has been successfully employed in oral mucosal PMDs and also in tumors of the cervix, lung and biliary tract.

Aims:

In this study, we intend to assess the ploidy status of exfoliated cells in OLP using DIC.

Materials and Methods:

Exfoliated cells from 48 patients with different subtypes of OLP (reticular, plaque type, erosive and atrophic) and 10 controls were stained using Feulgen reaction and assessed for integrated optical density using image analysis software and the ploidy status was assessed.

Results:

All the patients in the control group and most of the patients (93.5%) who had reticular or plaque type of OLP (29 out of 31) exhibited diploid nuclei in the smears, whereas 11 patients who had erosive or atrophic types of OLP showed aneuploid nuclei.

Conclusions:

The patients with erosive or atrophic types of OLP are at more risk and assessment of ploidy status by exfoliative cytology can be used as an adjuvant for diagnosis.

Expression of human DNA mismatch-repair protein, hMSH2, in patients with oral lichen planus

hMSH2 is one of the human DNA mismatch repair genes that plays an important role in reducing mutations and maintaining genomic stability. The aim of the present study was to detect the expression and significance of hMSH2 protein in patients with oral lichen planus (OLP). The expression levels of hMSH2 in the OLP group (n=51) and control group with normal oral mucosa (NM; n=40) were detected using an immunohistochemical method and subsequently assessed. The positive rate of hMSH2 expression in the OLP group was 52.94%, while the rate was 80% in the control group, exhibiting a statistically significant difference (χ²=7.1993; P<0.05). However, the expression of hMSH2 in the OLP tissues was not shown to significantly correlate with the patient gender, age and type of OLP (P>0.05). In conclusion, the protein expression levels of hMSH2 in the OLP tissues were significantly reduced as compared with that in the NM tissues, indicating that hMSH2 plays a role in the development of OLP. Therefore, hMSH2 may be used as a biomarker for evaluating the cancer risk of patients with OLP.

Malignant transformation of oral lichen planus by a chronic inflammatory process. Use of topical corticosteroids to prevent this progression?

BACKGROUND

Oral lichen planus is a potentially malignant disorder with a capacity, although low, for malignant transformation. Of all the factors related to the process of malignant transformation, it is believed that the chronic inflammatory process plays a key role in the development of oral cancer. This inflammatory process is capable of providing a microenvironment based on different inflammatory cells and molecules that affect cellular growth, proliferation and differentiation.

OBJECTIVES

The objectives of our study are: to review the available evidence about the possible relationship between the chronic inflammatory process present in oral lichen planus and its malignant transformation, to discuss the potential therapeutic implications derived from this relationship and to study the role that topical corticosteroids play in the control of oral lichen planus inflammation and its possible progression to malignant transformation.

CONCLUSION

The maintenance of a minimum dose of topical corticosteroids could prevent the inflammatory progression of oral lichen planus to oral cancer.

Prescribing for mucosal disease in primary dental care

Oral mucosal disease has a variety of causes, some of which are due to dysfunction of the immune system. Recurrent aphthous stomatitis and oral lichen planus are the mucosal diseases of unknown cause seen most frequently in dental practice, and the most likely mucosal diseases for which a dentist will prescribe. This paper briefly reviews the clinical features of these conditions, their causation and pertinent information for managing them in a primary care setting. The prescribing of appropriate medications to treat the conditions in a general dental practice is described and discussed.

Cytomorphometric analysis of exfoliated cells in oral lichen planus

BACKGROUND

Tumors are distinguished from normal tissues partly by their pronounced variability of cellular and nuclear dimensions. Therefore, such factors may be an indicator to assess whether the cells are malignant or not. Exfoliative cytology is a reliable tool in assessing such changes in the uterine cervix and has been used in the oral cavity also with success. The aims and objectives of the following study were to evaluate the malignant changes by assessing the quantitative parameters such as cytoplasmic diameter, cytoplasmic perimeter and cytoplasmic area (CD, CP, CA) and nuclear diameter, nuclear perimeter and nuclear area (ND, NP, NA) and cytoplasmic to nuclear ratio in the exfoliated cells of various subtypes of oral lichen planus (OLP) using cytomorphometry.

MATERIALS AND METHODS

Oral exfoliated cells from nineteen cases of histologically proven OLP (1 atrophic, 13 reticular, 4 erosive and 1 plaque) and ten controls with healthy mucosa were taken and stained by Feulgen-Rossenback reaction and cytomorphometric analysis was performed using an image analysis software. The parameters taken into account were CD, CP, CA and ND, NP, NA. Furthermore CA/NA was calculated. The parameters were statistically analyzed using the t-test.

RESULTS

Cytomorphometric analysis of all the parameters showed no significant difference between the control group and the reticular/plaque subtypes, whereas statistically significant (P < 0.05) differences was obtained between the control group and the atrophic/erosive subtypes group when compared using t-test.

CONCLUSIONS

The cytomorphometric analysis of OLP shows that erosive/atrophic subtypes of OLP are at more risk and exfoliative cytology and cytomorphometry can be used as a tool to assess the malignant changes.

Salivary interleukin-6 and -8 in patients with oral cancer and patients with chronic oral inflammatory diseases

BACKGROUND

Previous research has indicated that salivary interleukin (IL)-6 and IL-8 are potential biomarkers for oral squamous cell carcinoma (OSCC). However, their levels have been found to be significantly elevated in patients with chronic periodontitis (CP) or oral lichen planus (OLP). The data also showed wide variations in levels among the different studies, and no standardization procedure was ever performed. Therefore, the objective of this study is to determine whether CP or OLP confounds the use of IL-6 or IL-8 for OSCC detection.

METHODS

Saliva samples were collected from five groups: OSCC before treatment (n = 18); CP (n = 21); disease-active OLP (n = 21); disease-inactive OLP (n = 20); and healthy controls (n = 21). IL-6 and IL-8 concentrations (determined by enzyme-linked immunosorbent assays) were compared, using total salivary protein-standardized levels to validate the data. The Kruskal-Wallis test (α = 0.05) followed by pairwise Mann-Whitney U (post hoc) tests with Bonferroni adjustments (α = 0.00625) were used for statistical analysis.

RESULTS

Salivary IL-6 levels were significantly higher in patients with OSCC than in patients with CP (P <0.001), disease-active OLP (P = 0.001), disease-inactive OLP (P <0.001), and healthy controls (P <0.001). Salivary IL-8 levels were significantly higher in patients with OSCC than in patients with CP (P <0.001), but only marginally significantly higher than in healthy controls (P = 0.014). Statistical results of standardized IL-6 and IL-8 levels were consistent with the non-standardized levels in all pairs except one.

CONCLUSION

Salivary IL-6 may be a useful biomarker in the detection of OSCC, unconfounded by CP or OLP.

Clinicopathological features and malignant transformation of oral lichen planus: a 12-years retrospective study

OBJECTIVE

Oral lichen planus (OLP) is known to be associated with the risk of developing oral squamous cell carcinoma (OSCC). The objective of this study was to investigate the clinicopathological features of OLP and the prevalence of malignant transformation in this setting.

MATERIALS AND METHODS

This retrospective study was carried out on 204 medical records of patients with histologically proven OLP who received long-term follow-up (range 6 months-12 years). Data were entered in an informatic database. The statistical analysis, when needed, was performed with the chi-squared test for significance (p < 0.05).

RESULTS

At the moment of the diagnosis, out of 204 patients (163 female and 41 male; mean age 54.5 years), 107 patients (52.45%) suffered from systemic chronic diseases, in particular 46 (22.5%) from hepatitis C. Clinically, the reticular form of OLP was the predominant one and most patients had multiple oral sites of involvement. Fourteen patients showed extra-oral lesions. A percentage of malignant transformation less than 1% was found. In fact, two patients (0.98%) underwent a malignant transformation at a site previously diagnosed as OLP.

CONCLUSIONS

At present, OLP is accepted as being a potential malignant disorder, therefore lifelong follow-up is recommended.

Oral lichen planus: a retrospective study of 633 patients from Bucharest, Romania

Objective: In this retrospective study, patients’ medical records were reviewed to investigate the profiles of 633 OLP cases in a group of Romania. Material and Methods: In this retrospective study, the following clinical data were obtained from the medical charts of patients: gender, age, clinical presentation of OLP, site affected, presence of symptoms, extraoral manifestations of lichen planus, presence of systemic diseases, and history of medications. Results: Most (78.67%) OLP patients were female and the mean age at presentation was 52 years. The white type of the disease (reticular/papular/plaque lesions) was the main form encountered in this sample (48.97%). Among patients with available hepatitis C virus test results, 9.6% were serum-positive. OLP was associated with gallbladder disease (i.e. cholecystitis, cholelithiasis) in 19% of patients. Six patients (0.95%) developed squamous cell carcinoma at a site with confirmed OLP lesions. Conclusions: To the best of our knowledge, no similar study has been conducted in a Romanian population. The present investigation revealed the predominance of OLP among middle-aged white women and the prevalence of bilateral involvement of the buccal mucosa with reticular white lesions. Anti-HCV circulating antibodies were more common in patients with OLP than in the general population and, notably, OLP was associated with gallbladder disease (cholecystitis, cholelithiasis) in 19% of patients.

Key words:Oral lichen planus, oral mucosal diseases, retrospective study.

Urban legends series: oral leukoplakia

To date, the term oral leukoplakia (OL) should be used to recognize 'predominantly white plaques of questionable risk, having excluded (other) known diseases or disorders that carry no increased risk of cancer'. In this review, we addressed four controversial topics regarding oral leukoplakias (OLs): (i) Do tobacco and alcohol cause OLs?, (ii) What percentage of OLs transform into oral squamous cell carcinoma (OSCC)?, (iii) Can we distinguish between premalignant and innocent OLs?, and (iv) Is proliferative verrucous leukoplakia (PVL) a specific entity or just a form of multifocal leukoplakia? Results of extensive literature search suggest that (i) no definitive evidence for direct causal relationship between smoked tobacco and alcohol as causative factors of OLs, (ii and iii) the vast majority of OLs follow a benign course and do not progress into a cancer, and no widely accepted and/or validated clinical and/or biological factors can predict malignant transformation, and (iv) the distinction between multifocal/multiple leukoplakias and PVL in their early presentation is impossible; the temporal clinical progression and the high rate of recurrences and development of cancer of PVL are the most reliable features for diagnosis.