Oral lichen planus and malignant transformation: is a recall of patients justified?

Utilizing deep learning for automated detection of oral lesions: A multicenter study

OBJECTIVES

We aim to develop a YOLOX-based convolutional neural network model for the precise detection of multiple oral lesions, including OLP, OLK, and OSCC, in patient photos.

MATERIALS AND METHODS

We collected 1419 photos for model development and evaluation, conducting both a comparative analysis to gauge the model's capabilities and a multicenter evaluation to assess its diagnostic aid, where 24 participants from 14 centers across the nation were invited. We further integrated this model into a mobile application for rapid and accurate diagnostics.

RESULTS

In the comparative analysis, our model overperformed the senior group (comprising three most experienced experts with more than 10 years of experience) in macro-average recall (85 % vs 77.5 %), precision (87.02 % vs 80.29 %), and specificity (95 % vs 92.5 %). In the multicenter model-assisted diagnosis evaluation, the dental, general, and community hospital groups showed significant improvement when aided by the model, reaching a level comparable to the senior group, with all macro-average metrics closely aligning or even surpassing with those of the latter (recall of 78.67 %, 74.72 %, 83.54 % vs 77.5 %, precision of 80.56 %, 76.42 %, 85.15 % vs 80.29 %, specificity of 92.89 %, 91.57 %, 94.51 % vs 92.5 %).

CONCLUSION

Our model exhibited a high proficiency in detection of oral lesions, surpassing the performance of highly experienced specialists. The model can also help specialists and general dentists from dental and community hospitals in diagnosing oral lesions, reaching the level of highly experienced specialists. Moreover, our model's integration into a mobile application facilitated swift and precise diagnostic procedures.

Salivary metabolomics in patients with oral lichen planus: a preliminary study based on NMR spectroscopy

OBJECTIVES

The present preliminary study aimed to investigate the salivary metabolic profile in patients with asymptomatic oral lichen planus (OLP) using nuclear magnetic resonance (NMR) spectroscopy.

MATERIAL AND METHODS

Stimulated whole mouth saliva (SWMS) samples were collected from 15 reticular OLP female patients and 15 from age- and sex-matched controls (HCs). A total of 23 metabolites were identified and quantified. Mann-Whitney's U test was used to compare the determined concentration salivary metabolite concentrations between OLP patients and the healthy controls.

RESULTS

The concentration of acetate, methylamine, and pyruvate was elevated, whereas the concentration of tyrosine was decreased in the saliva of OLP patients compared with HCs. To identify a combination of metabolites, multivariate discrimination function analysis (DFA) was conducted. DFA analysis have shown that the most powerful discrimination between the groups was achieved when methylamine and tyrosine were considered as combined biomarkers.

CONCLUSIONS

Salivary tyrosine was of particular interest and a promising finding for the screening of OLP and its progression. Further longitudinal studies are required to establish it as a reliable salivary biomarker in OLP.

CLINICAL RELEVANCE

The salivary metabolic profiling can describe the pathologic characteristics of OLP on non-invasive saliva samples and NMR analysis. Salivary metabolites provide details to considered early detectors and to impact oral health of OLP patients.

Bridging the gaps: management of lichen planus subtypes in a joint dermatology-oral surgery clinic

Lichen planus (LP) presents with a range of clinical subtypes. It can affect the outer skin, involve the nails and present with alopecia and mucosal symptoms to varying degrees. LP of the outer skin mostly shows a self-limiting course; however, this is not the case for lichen planopilaris and the mucosa-affecting subtypes. The pathogenesis of LP is still incompletely understood. As a result, an effective, targeted therapy is currently lacking and different immunomodulatory approaches are being used in clinical practice. The management of patients with severe oral LP mucosae can be particularly challenging. Although the true risk remains controversial, oral LP is considered a risk factor for the development of squamous cell carcinoma and there is a need for regular screening. The quality of life in patients with LP is significantly impaired because of frequent clinical visits, pain, soreness, inability to eat certain foods, side effects to medication, frustrating therapy attempts and worry regarding cancer risk. We highlight here the advantages of an interdisciplinary dermatology and oral surgery clinic, which can address the domains of tooth status, nutrition, pain and malignant transformation and optimized patient management.

Different Treatment Modalities of Oral Lichen Planus-A Narrative Review

Oral lichen planus (OLP) is a chronic inflammatory disease of unknown etiology which affects the oral mucosa. OLP varies in its clinical features from a reticular form that is, in most cases, asymptomatic, to atrophic-erosive, and is accompanied by symptoms of burning sensation and pain followed by difficulty in eating. Given the fact that OLP is a disease of unknown etiology, the treatment is symptomatic and involves suppressing the signs and symptoms of the disease using various topical and systemic drugs. The first line of therapy for treating symptomatic OLP is topical corticosteroids, whereas systemic corticosteroids are used for treating persistent lesions that do not respond to local treatment. However, the lack of convincing evidence on the efficacy of previous therapies, including topical corticosteroids, and numerous side effects that have appeared over recent years has resulted in the emergence and development of new therapeutic options. Some of the therapies mentioned are tacrolimus, efalizumab, dapson, interferon, retinoic acid, photochemotherapy with psoralen and ultraviolet A rays (PUVA), aloe vera, antimalarials, antibiotics and others. These therapies only partially meet the properties of efficacy and safety of use, thus justifying the continuous search and testing of new treatment methods.

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.

A Survey of Brazilian Patients with Oral Lichen Planus Showing No Evidence of Malignancy

Objectives

There is conflicting evidence as to whether oral lichen planus (OLP) can undergo malignant transformation into oral squamous cell carcinoma (OSCC). This study aimed to address this issue by analyzing a sample of Brazilian patients with either OLP or OSCC. Patients and Methods. This study was conducted in São Paulo, the world's fourth-largest city by population. Two groups of patients were analyzed. The OLP group consisted of 370 patients, while the OSCC group consisted of 154 patients. The OLP patients were followed up for up to 21 years to monitor clinical benefits from the management or changes in the lesion morphology; conversely, patients with OSCC were examined only twice for diagnostic purposes and referred to a specialized center. Data concerning systemic diseases, use of medications, type of oral lesions, and health-risk behaviors were recorded for patients in both groups.

Results

None of the patients with OLP developed OSCC at the lesion site. Only one female patient with erosive OLP developed OSCC in the normal, lesion-free oral mucosa. None of the OSCC patients had concomitant OLP lesions; however, a higher percentage of OSCC cases (17.5%) showed white plaques (most likely oral leukoplakia) as a precursor lesion.

Conclusion

The findings strongly suggest that malignant transformation of OLP is virtually nonexistent in the Brazilian population.

Correlation between WHO and Modified WHO Classification Systems in the Histopathologic Diagnosis of Oral Lichen Planus Using Intraobserver and Interobserver Variability

Background

Oral lichen planus (OLP) is a relatively common chronic autoimmune disease. In the present study, we tried to correlate the histopathological criteria of WHO and modified WHO (mod.WHO) classification systems using two methods, namely, intraobserver and interobserver observations in these samples.

Methods

This cross-sectional study was performed on 64 microscopic slides with the diagnosis of the OLP lesions, based on both clinical and histopathological features. At first, each pathologist individually (as intraobserver) examined microscopic slides based on both histopathologic diagnostic criteria. Later, three pathologists in a group (as interobserver) reevaluated microscopic slides 2 months later in the second phase of the study, based on both systems. Eventually, the findings were statistically analyzed with Cohen's kappa coefficient (κ) and reported.

Results

According to the results, the lichen planus was detected in 8 cases using the WHO method, and in 41 cases using the Mod.WHO method. Intrarater Kappa coefficients were κ = 0.114, P = 0.299; κ = 0.181, P = 0.012; and κ = 0.062, P = 0.424 for three pathologists, respectively. The findings showed no reproducibility (κ = 0.148, P = 0.024) and there was no correlation between the two systems. Statistical analysis revealed that the histopathological criteria of the WHO classification for detecting the lichen planus microscopy were more sensitive but the Mod.WHO classification criteria were more specific for detecting the lichen planus.

Conclusions

Due to the higher specificity of the histopathological criteria of Mod.WHO classification rather than WHO classification, it seems that Mod.WHO classification has more important and useful criteria for histopathological diagnosis. Finally, we can conclude that the use histopathologic criteria of the Mod.WHO classification is more useful in the diagnosis of lichen planus, although it should be in combination with clinical information.

Role of Human Papilloma Virus in Malignant Transformation of Oral Lichen Planus: A Systematic Review

Lichen planus (LP) is a chronic inflammatory mucocutaneous disease. The disease has a cell-mediated immune reaction which is precipitated by a specific trigger which turns the self-peptides antigenic. The role of human papillomavirus (HPV) in the malignant transformation of oral LP (OLP) has always been debated. Establishing a definitive part played by HPV in the malignant transformation of OLP, would possibly provide screening for the viruses, HPV vaccination, and antiviral therapy along with conventional treatment in LP which could improve prognosis. This systematic review is to assess the role of HPV in the malignant transformation of OLP. We performed a systematic search of PubMed, MEDLINE, and Google. The information was extracted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All full-text papers that assessed the association of HPV in malignant transformation of OLP were considered eligible. The outcome parameter included the malignant transformation of OLP. We found a total of 19 studies from which five were found suitable for the review. Results from this systematic review showed HPV is associated with OLP. There is an increased prevalence of HPV in the erosive-atrophic (EA) variant of OLP compared to non-EA variant. There seems to be no strong evidence to prove the association between HPV and malignant transformation of OLP. Taking up the oncogenic potential of high-risk types and OLP as a potentially malignant disorder, more number of studies need to be performed on the dysplastic subtype of OLP and in those OLP lesions that progress to oral squamous cell carcinomas.

An active surveillance program in oral preneoplasia and translational oncology benefit

OBJECTIVE

We desired to establish an active surveillance clinic for head and neck cancer. In this review we examined.

METHODS

We examined the natural history of human oral carcinogenesis, the types of preneoplastic lesions, and efforts at oral chemoprevention over the past decades for presentation here.

RESULTS

We established a clinic and program for patients with oral premalignant lesions approximately over 15 years ago based on an unmetneed for this service. We have completed over 4000 outpatient visits for this cohort and have a place for referrals of difficult oral lesions. We have leveraged this population for multiple federally funded trials on oral cancer prevention as well as specimen banking.

CONCLUSION

There is need for routine active surveillance for oral preneoplastic conditions in patients at high risk for conversion to cancer. There are no effective durable treatment or preventions for these individuals and we have attempted to fill this unmet need with our program.

Oral potentially malignant disorders: clinical diagnosis and current screening aids: a narrative review

Around 300 000 patients are estimated to have oral cancer worldwide annually, and the incidence is higher in South Asian countries. In 2005, at the Congress of WHO, the term potentially malignant disorder (PMD)/lesion was suggested as a replacement for premalignant oral lesions and conditions. PMDs are those lesions of the oral mucosa that are at an increased risk of malignant transformation compared with the healthy mucosa. PMDs consist of leukoplakia, erythroplakia, oral lichen planus, oral submucous fibrosis, and other miscellaneous lesions. A literature search was performed using PubMed, Scopus, and Web of Science without any language restrictions. There is no standardized method for identifying a site for biopsy and various methods such as toluidine blue stain, methylene blue, Lugol's iodine, and chemiluminescence have been proposed in the literature. Despite easy access to the oral cavity, there has been significant mortality associated with oral cancer as they are often diagnosed late because of the inability of healthcare professionals to identify them at early premalignant states. This article aims to provide healthcare professionals with the knowledge to identify potentially malignant disorders and to aid them in biopsy site identification.

Malignant transformation of oral lichen planus: a retrospective study of 565 Japanese patients

Background

Oral lichen planus (OLP) is a chronic inflammatory oral mucosa disease that is recognized as an oral potentially malignant disorder. However, the potentially malignant nature of OLP remains unclear.

Methods

We designed this study to examine the demographic and clinical characteristics of patients with OLP and evaluate the associated malignant transformation rate. A total of 565 patients with a clinical and histopathological diagnosis of OLP who presented at our department between 2001 and 2017 were retrospectively studied. Patients who had clinical and histopathological features of oral lichenoid lesions (OLLs) classified as oral lichenoid contact lesions, oral lichenoid drug reactions and oral lichenoid lesions of graft-versus-host disease were excluded.

Results

The study population included 123 men and 442 women aged 21–93 years (mean ± standard deviation, 60.5 ± 11.8). The 565 patients were followed up for a duration of 55.9 ± 45.3 months, during which 4 (0.7%) patients developed squamous cell carcinoma (SCC). In three of these 4 patients who developed SCC, the clinical type of OLP was the red type.

Conclusions

Our results suggested that OLP was associated with a low risk of malignant transformation. We recommend regular follow-up for OLP patients and clear differentiation of oral epithelial dysplasia and OLLs to enable early detection of malignant transformation. Further investigation of the clinical risk factors associated with malignant transformation is necessary.

Treatment trends in oral lichen planus and oral lichenoid lesions (Review)

Oral lichen planus (OLP) is a chronic inflammatory disease, associated with altered cell-mediated immunological function. It has long-term evolution, repeated exacerbations, sometimes painful and resistant to treatment, even all of these, OLP significantly affects patient's life quality. Not least, OLP is accompanied by an increased risk of malignant transformation. A wide spectrum of therapeutic options is available, but none are curative. In this review, 58 structured studies on the clinical symptomatology and treatment strategy of OLP were analyzed. The literature research was performed according to the criteria of the PRISMA system. This study summarizes current knowledge regarding management of OLP and oral lichenoid lesions, discusses the challenges of choosing an adequate treatment and, in attempt to improve the quality of patient life, trying to describe a therapeutic algorithm that takes into consideration the clinical features of the disease. Current OLP therapy aims at eliminating all mucosal-related lesions, reduce symptomatology and decrease the risk of oral cancer and include corticosteroids, immunomodulatory agents, retinoids, ultraviolet irradiation and/or laser therapy.

Reflectance confocal microscopy characteristics of oral lichen planus: An analysis of 47 cases in a Chinese cohort

Reflectance confocal microscopy (RCM) is a non-invasive tool that provides real-time microscopic images and relatively high-resolution tissue images. This technique provides a link between clinical examination and histopathology. RCM has been used to detect skin diseases and has also recently been applied to diseases of the oral mucosa. The present study aimed to explore the features of oral lichen planus (OLP) using RCM. A total of 47 patients with OLP exhibiting a reticular pattern, were included in the present study. The lesion sites and healthy adjacent sites were examined using in vivo RCM, with the lesion being histopathologically confirmed after RCM examination. The confocal images were reviewed, and the features were described. Sensitivity and specificity analysis of the RCM features was also performed. RCM examination presented parakeratosis, acanthosis and connective tissue papillae disappearance, with the presence of large melanocytes and roundish inflammatory cell infiltration, as well as dilated vessels in the lesion tissue. The sensitivity and specificity of OLP for dorsal tongue lesions were not as satisfactory as those on other sites. The results implied that RCM may be a promising technique to detect OLP non-invasively in vivo.

Sex Hormones and Inflammation Role in Oral Cancer Progression: A Molecular and Biological Point of View

Oral cancers have been proven to arise from precursors lesions and to be related to risk behaviour such as alcohol consumption and smoke. However, the present paper focuses on the role of chronic inflammation, related to chronical oral infections and/or altered immune responses occurring during dysimmune and autoimmune diseases, in the oral cancerogenesis. Particularly, oral candidiasis and periodontal diseases introduce a vicious circle of nonhealing and perpetuation of the inflammatory processes, thus leading toward cancer occurrence via local and systemic inflammatory modulators and via genetic and epigenetic factors.

Non-plaque-induced gingival diseases

While plaque-induced gingivitis is one of the most common human inflammatory diseases, several non-plaque-induced gingival diseases are less common but often of major significance for patients. The non-plaque-induced gingival lesions are often manifestations of systemic conditions, but they may also represent pathologic changes limited to gingival tissues. A classification is proposed, based on the etiology of the lesions and includes: Genetic/Developmental disorders; Specific infections; Inflammatory and immune conditions and lesions; Reactive processes; Neoplasms; Endocrine, Nutritional and metabolic diseases; Traumatic lesions; and Gingival pigmentation.

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.

Oral lichen planus and associated comorbidities: An approach to holistic health

Lichen planus (LP) is a chronic inflammatory disorder with involvement of skin, oral and genital mucosa, scalp, and nail appendages. Oral lichen planus (OLP) lesions demonstrate a number of morphologic presentations, persist for a long time with rare self-resolution, and undergo malignant changes. OLP has been associated with numerous systemic connotations such as metabolic syndrome, diabetes mellitus, hypertension, thyroid diseases, psychosomatic ailments, chronic liver disease, gastrointestinal diseases, and genetic susceptibility to cancer. The oral health physician should be aware of these systemic associations and should work in close connect with the primary healthcare physicians to rule out the predisposing factors for the associated comorbidities. This article aims to highlight the various systemic associations of OLP and warrants the screening of these ailments in OLP for prevention and effective management.

Non-plaque-induced gingival diseases

While plaque-induced gingivitis is one of the most common human inflammatory diseases, several non-plaque-induced gingival diseases are less common but often of major significance for patients. The non-plaque-induced gingival lesions are often manifestations of systemic conditions, but they may also represent pathologic changes limited to gingival tissues. A classification is proposed, based on the etiology of the lesions and includes: Genetic/Developmental disorders; Specific infections; Inflammatory and immune conditions and lesions; Reactive processes; Neoplasms; Endocrine, Nutritional and metabolic diseases; Traumatic lesions; and Gingival pigmentation.

Head and neck cancer in living donor liver transplant recipients: Single center retrospective study

The purpose of this study was to investigate the incidence and risk factors of head and neck cancer in living donor liver transplant (LDLT) recipients.This is a retrospective cohort study. A case-matched (1:4) comparison between recipients with and without developed head and neck cancer after LDLT was conducted. The differences between 2 groups were analyzed.The incidence of head and neck malignancy in our cohort was 9 of 453 (1.98%). Their cumulative survival rate was below 60% at 24 months after the diagnosis of head and neck cancer, and no recipients lived for more than 2 years after being diagnosed with stage IV cancer. In the case-control study, univariate analysis revealed that alcohol consumption (odds ratio [OR] = 8.75, 95% confidence interval [CI]: 1.55-49.56) and smoking (OR = 6.71, 95% CI: 1.20- 37.44) were factors associated with the incidence of head and neck cancer after LDLT.In the conclusion, recipients with head and neck cancer after LDLT may have a rather poor prognosis, especially those who are initially diagnosed with advanced-stage disease. Alcohol consumption and smoking may be the predisposing factors to head and neck cancer in LDLT recipients.

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.

How general dentists could manage a patient with oral lichen planus

BACKGROUND

The literature hardly contains information on how patients suffering from oral lichen planus could be managed by dentists.

MATERIAL AND METHODS

Based on the limited available literature and particularly on the long-term clinical and histopathological experience of one of the authors, suggestions on how dentists could manage patients with oral lichen planus have been put forward.

RESULTS

In most cases, the dentist should be able to establish a correct diagnosis. Occasionally, the dentist may call upon a specialist, usually an oral medicine specialist or an oral and maxillofacial surgeon for confirmation of the diagnosis, possibly a biopsy procedure, and management of the patient in case of severe symptoms. Proper patient information is of utmost importance in the management.

CONCLUSIONS

General dentists can be expected to manage the majority of patients with oral lichen planus. Some patients may need to be referred for diagnostic purposes to a specialist; this is also the case for the rare patient with severe symptoms, possibly requiring systemic treatment.

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.

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.

Molecular markers in oral lichen planus: A systematic review

Oral lichen planus (OLP) is a chronic inflammatory mucosal disease that is usually detected in 0.5–2.2% of the human population. Among these, only 0.5–2.9% of the lesions progress to carcinoma. However, there are no prognostic markers available presently to recognize the increased risk in malignant transformation of the lesions. Selected markers for cell proliferation, adhesion, apoptosis and lymphocytic infiltration were analyzed by immunohistochemistry in addition to static cytometry for DNA content. The concept linking OLP and oral squamous cell carcinoma states that chronic inflammation results in crucial DNA damage, which further progresses to development of carcinoma. Even though in the past decade, enormous information has been accumulated on malignant potential of OLP, its transformation still remains unclear. Hence, the purpose of this article was to review cellular and molecular markers to understand the pathogenesis of OLP and its progression toward malignancy.

Epidemiology of Oral Lichen Planus in a Cohort of South Indian Population: A Retrospective Study

BACKGROUND

Oral lichen planus (OLP) is an immune-mediated potentially malignant disorder of the oral cavity. Dysplastic OLP has an altered cytogenic profile and can progress into oral squamous cell carcinoma. The epidemiology of OLP is well-described in several relatively large series from various geographic locations, whereas such series from southern India is rare. The aim of the present study was to determine the epidemiology of OLP in a cohort of South Indian population.

METHODS

All the case data records of 29,606 patients who visited Mar Baselios Dental College and Hospital, Kerala, India from 2014 to 2015 were retrospectively reviewed. For data review, 122 patients of OLP were selected Estimated were type, number, and location of lesions, clinical manifestation, age of the patient, gender, onset and duration of lesion, stressful life style, habits, skin involvement and associated systemic illness, and presence/absence of dysplasia.

RESULTS

When the distribution of OLP among the gender was considered, we found more prevalence in females than males. Fifty-seven percent of patients were associated with stressful lifestyle. Reticular lichen planus was the most common clinical subtype found. Bilateral buccal mucosal was the common site, when the distribution of sites of OLP were compared (P < 0.05). Hypersensitivity reaction was frequently associated with systemic illness with OLP (P < 0.05). Anaplasia was found among 5% of lichen planus lesions.

CONCLUSIONS

OLP patients had high incidence of hypersensitivity reactions and 5% of OLP lesions showed anaplasia. Long term follow-up is necessary to monitor the recurrence, prognosis, and malignant transformation of OLP.

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.

Dysplastic change rate in cases of oral lichen planus: A retrospective study of 112 cases in an Iranian population

Backgrounds:

Lichen planus is a chronic systemic disease and oral mucosa is commonly involved. Oral lichen planus (OLP) most commonly affects middle-aged women. The prevalence of the disease ranges between 0.5% and 2.6% in the general population and the range of malignant transformation varies between 0% and 10%.

Objectives:

To assess the rate of malignant transformation of OLP samples.

Materials and Methods:

This retrospective study was carried out on 112 medical records of patients with histological diagnosis of OLP who attended the Department of Pathology at the Educational Hospital from 2005 to 2012. H&E-stained slides were reviewed by two pathologists using strict clinical and histopathological diagnostic World Health Organization (WHO) criteria. Dysplastic changes were diagnosed and graded according to the latest WHO classification.

Results:

Of the 112 cases diagnosed as OLP, there were 39 males and 73 females and the patients’ ages ranged from 15 to 86 years (mean age 44.5 years). The erosive form with fifty cases was the most common clinical type and the papular type with one case was the least common clinical type. Regarding the site, the buccal mucosa was the most common site with 52 cases. Totally, dysplastic changes were found in 12 samples, among them five cases showed mild dysplasia and seven cases showed moderate dysplasia. One case developed oral squamous cell carcinoma after 3 years.

Conclusion:

OLP is considered as a premalignant condition by the WHO and several authors. Although the malignancy rate is not so high, to reduce morbidity and mortality from cancer arising on OLP lesions, a regular follow-up examination is recommended.

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 precursor lesions and malignant transformation--who, where, what, and when?

Oral potentially malignant disorders (PMD) are recognisable mucosal conditions that have an unpredictable risk of transformation to squamous cell carcinoma (SCC), a lethal and deforming disease of rising incidence. Contemporary management is based on clinical recognition of suspicious lesions and incisional biopsy to enable histopathological assessment and grading of dysplasia, together with excision of high-risk lesions and long-term surveillance. However, it is impossible to predict clinical outcome or risk of malignant transformation. Our aim was to evaluate the relevance of previously identified oral precursor lesions for the development of SCC and staging of disease. We therefore retrospectively reviewed 1248 cases of SCC diagnosed in oral and maxillofacial surgery units at Newcastle upon Tyne and Sunderland hospitals between 1996 and 2009. Of them, 58 identifiable precursor lesions became malignant but only 25 had been dysplastic on initial biopsy; 19 of 33 non-dysplastic lesions exhibited lichenoid inflammation only. SCC arose most often on the ventrolateral tongue and floor of the mouth, with a mean transformation time of 29.2 months. Transformation time was significantly shorter in men (p=0.018) and those over 70 years of age (p=0.010). Patients who consumed more than 21 units of alcohol/week and those who had had interventional laser surgery to treat precursor lesions, had higher-staged tumours (p=0.048). Although retrospective, this study shows that the results of incisional biopsy and grading of dysplasia have limited use as predictive tools, and supports the view that cancer may arise in the absence of recognisable epithelial dysplasia. Our findings confirm the importance of clinical vigilance and active surveillance in the management of all patients with clinically suspicious oral lesions, irrespective of the histological findings.

Epigenetic Modifications and Accumulation of DNA Double-Strand Breaks in Oral Lichen Planus Lesions Presenting Poor Response to Therapy

Epigenetics refers to changes in cell characteristics that occur independently of modifications to the deoxyribonucleic acid (DNA) sequence. Alterations mediated by epigenetic mechanisms are important factors in cancer progression. Although an exciting prospect, the identification of early epigenetic markers associated with clinical outcome in premalignant and malignant disorders remains elusive. We examined alterations in chromatin acetylation in oral lichen planus (OLP) with distinct clinical behavior and compared the alterations to the levels of DNA double-strand breaks (DSBs). We analyzed 42 OLP patients, who had different responses to therapy, for acetyl-histone H3 at lys9 (H3K9ac), which is associated with enhanced transcription and nuclear decondensation, and the presence of DSBs, as determined by accumulation of phosphorylated γH2AX foci. Patients with high levels of H3K9ac acetylation failed to respond to therapy or experienced disease recurrence shortly after therapy. Similar to H3K9ac, patients who responded poorly to therapy had increased accumulation of DNA DSB, indicating genomic instability. These findings suggest that histone modifications occur in OLP, and H3K9ac and γH2AX histones may serve as epigenetic markers for OLP recurrence.

Photodynamic therapy in treatment of oral lichen planus

Oral lichen planus (OLP) is a relatively common chronic immunologic mucocutaneous disorder. Although there are many presenting treatments, some of them proved its failure. Recently, the use of photodynamic therapy (PDT) has been expanding due to its numerous advantages, as it is safe, convenient, and non-invasive and has toxic effect towards selective tissues. This article provides comprehensive review on OLP, its etiology, clinical features and recent non-pharmacological treatments. We also describe the topical PDT and its mechanisms. Our purpose was to evaluate the efficacy of PDT in treatment of OLP through collecting the data of the related clinical studies. We searched in PubMed website for the clinical studies that were reported from 2000 to 2014 using specific keywords: "photodynamic therapy" and "treatment of oral lichen planus". Inclusion criteria were English publications only were concerned. In the selected studies of photodynamic treatment, adult patients (more than 20 years) were conducted and the OLP lesions were clinically and histologically confirmed. Exclusion criteria were classical and pharmacological treatments of OLP were excluded and also the using of PDT on skin lesions of lichen planus. We established five clinical studies in this review where all of them reported improvement and effectiveness of PDT in treatment of OLP lesions. The main outcome of comparing the related clinical studies is that the photodynamic is considered as a safe, effective and promising treatment modality for OLP.

Quantitative Analysis of Salivary TNF-α in Oral Lichen Planus Patients

Objective. The aim of this study was to quantitatively evaluate the salivary tumor necrosis factor-alpha (TNF-α) level in oral lichen planus patients and to compare the levels of TNF-α between saliva and serum of OLP and controls. Methods. Serum and whole saliva from 30 patients with active lesions of oral lichen planus (OLP) and 30 healthy persons were investigated for the presence of TNF-α by enzyme immunoassay. Student's independent t-test and two-sample binomial proportion test were used to calculate significance of the mean values of TNF-alpha in serum and saliva and to determine the proportions of the detected and nondetected samples in both groups. Results. Proportion of detection and the mean of detectability between saliva and serum of Group B show an almost equal value, which suggests that saliva can be a good alternate to serum to analyze TNF-α in oral lichen planus patients.

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.

Oral potentially malignant disorders: is malignant transformation predictable and preventable?

Leukoplakia is the most common potentially malignant disorder of the oral mucosa. The prevalence is approximately 1% while the annual malignant transformation ranges from 2% to 3%. At present, there are no reliable clinicopathological or molecular predicting factors of malignant transformation that can be used in an individual patient and such event can not truly be prevented. Furthermore, follow-up programs are of questionable value in this respect. Cessation of smoking habits may result in regression or even disappearance of the leukoplakia and will diminish the risk of cancer development either at the site of the leukoplakia or elsewhere in the mouth or the upper aerodigestive tract. The debate on the allegedly potentially malignant character of oral lichen planus is going on already for several decades. At present, there is a tendency to accept its potentially malignant behaviour, the annual malignant transformation rate amounting less than 0.5%. As in leukoplakia, there are no reliable predicting factors of malignant transformation that can be used in an individual patient and such event can not truly be prevented either. Follow-up visits, e.g twice a year, may be of some value. It is probably beyond the scope of most dentists to manage patients with these lesions in their own office. Timely referral to a specialist seems most appropriate, indeed.

Key words:Oral potentially malignant disorders, oral leukoplakia, oral lichen planus.

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.

PPARγ in head and neck cancer prevention

Head and neck cancer is a major source of morbidity and mortality worldwide. Intervention during the early phases of carcinogenesis represents a promising new strategy for curbing the devastating effects of this disease and its primary treatment modalities, surgery and radiation with or without concomitant chemotherapy. This review focuses on the peroxisome proliferator-activated receptor gamma (PPARγ) as a target for chemoprevention of oral cancer. Accumulating data suggest that ligands of PPARγ, which include the thiazolidinedione class of agents approved for the treatment of diabetes, inhibit cancer cell growth in vitro and in animal carcinogenesis models, providing the rationale for testing this approach in populations at risk for head and neck cancer.

Oral mucosal health in liver transplant recipients and controls

Immunosuppressive drugs and other medications may predispose patients to oral diseases. Data on oral mucosal health in recipients of liver transplantation (LT) are limited. We, therefore, recruited 84 LT recipients (64 with chronic liver disease and 20 with acute liver failure) for clinical oral examinations in a cross-sectional, case-control study. Their oral health had been clinically examined before transplantation. The prevalence of oral mucosal lesions (OMLs) was assessed in groups with different etiologies of liver disease and in groups with different immunosuppressive medications, and these groups were compared to controls selected from a nationwide survey in Finland (n = 252). Risk factors for OMLs were evaluated with logistic regression. OMLs were more frequent in LT recipients versus controls (43% versus 15%, P < 0.001), and the use of steroids raised the prevalence to 53%. Drug-induced gingival overgrowth was the single most common type of lesion, and its prevalence was significantly higher for patients using cyclosporine A (CSA; 29%) versus patients using tacrolimus (TAC; 5%, P = 0.007); the prevalence was even higher with the simultaneous use of calcium channel blockers and CSA (47%) or TAC (8%, P = 0.002). Lesions with malignant potential such as drug-induced lichenoid reactions, oral lichen planus-like lesions, leukoplakias, and ulcers occurred in 13% of the patients with chronic liver disease and in 6% of the controls. Every third patient with chronic liver disease had reduced salivary flow, and more than half of all patients were positive for Candida; this risk was higher with steroids. In conclusion, the high frequency of OMLs among LT recipients can be explained not only by immunosuppressive drugs but also by other medications. Because dry mouth affects oral health and OMLs may have the potential for malignant transformation, annual oral examinations are indicated.