An atypical verrucous carcinoma of the tongue arising in a patient with oral lichen planus associated with hepatitis C virus infection

Artificial Intelligence-Based Diagnosis of Oral Lichen Planus Using Deep Convolutional Neural Networks

OBJECTIVE

 The aim of this study was to employ artificial intelligence (AI) via convolutional neural network (CNN) for the separation of oral lichen planus (OLP) and non-OLP in biopsy-proven clinical cases of OLP and non-OLP.

MATERIALS AND METHODS

 Data comprised of clinical photographs of 609 OLP and 480 non-OLP which diagnosis has been confirmed histopathologically. Fifty-five photographs from the OLP and non-OLP groups were randomly selected for use as the test dataset, while the remaining were used as training and validation datasets. Data augmentation was performed on the training dataset to increase the number and variation of photographs. Performance metrics for the CNN model performance included accuracy, positive predictive value, negative predictive value, sensitivity, specificity, and F1-score. Gradient-weighted class activation mapping was also used to visualize the important regions associated with discriminative clinical features on which the model relies.

RESULTS

 All the selected CNN models were able to diagnose OLP and non-OLP lesions using photographs. The performance of the Xception model was significantly higher than that of the other models in terms of overall accuracy and F1-score.

CONCLUSIONS

 Our demonstration shows that CNN models can achieve an accuracy of 82 to 88%. Xception model performed the best in terms of both accuracy and F1-score.

Investigating the factors proposed in oral lichen planus malignant transformation: A literature review

Background and Aims

Lichen planus is a chronic inflammatory disease that affects about 1% of the world's population. The World Health Organization has included oral lichen planus among potentially malignant disorders. Identification of reliable biomarkers for the diagnosis of malignant transformation may play a unique role in the development of standard screening and improvement of follow-up in patients with oral precancerous lesions. It is currently assumed that the molecular pathways controlling growth, maturation, proliferation, and apoptosis in epithelial cells may play an important role in the process of transformation into malignancy.

Methods

The search was done in PubMed, Scopus, Google Scholar, Embase, and Cochrane databases from 1960 to 2022.

Results

Based on the inclusion criteria, 23 articles were included.

Conclusion

In this review of articles, 34 different biomarkers that have been investigated in studies for the possibility of malignant transformation in OLP have been studied. Among all the risk factors related to malignant transformation, most studies have been done on the role of cytokines and tumor suppressors, in fact, the chronicity of the lesion which is the result of the reaction between the repair and the inflammatory response and the responses accompanied by the secretion of cytokines, may play a major role in the malignant transformation of OLP.

Meet the Insidious Players: Review of Viral Infections in Head and Neck Cancer Etiology with an Update on Clinical Trials

Head and neck cancers (HNC) occur in the upper aerodigestive tract and are among the most common cancers. The etiology of HNC is complex, involving many factors, including excessive tobacco and alcohol consumption; over the last two decades, oncogenic viruses have also been recognized as an important cause of HNC. Major etiological agents of nasopharynx carcinoma and oropharyngeal carcinoma include Epstein-Barr virus (EBV) and human papillomaviruses (HPVs), both of which are able to interfere with cell cycle control. Additionally, the association of hepatitis C and hepatitis B infection was observed in oral cavity, oropharyngeal, laryngeal, and nasopharyngeal cancers. Overall prognoses depend on anatomic site, stage, and viral status. Current treatment options, including radiotherapy, chemotherapy, targeted therapies and immunotherapies, are distributed in order to improve overall patient prognosis and survival rates. However, the interplay between viral genome sequences and the health, disease, geography, and ethnicity of the host are crucial for understanding the role of viruses and for development of potential personalized treatment and prevention strategies. This review provides the most comprehensive analysis to date of a vast field, including HNC risk factors, as well as viral mechanisms of infection and their role in HNC development. Additionally, currently available treatment options investigated through clinical practice are emphasized in the paper.

Hepatitis C and Risk of Nonhepatic Malignancies

Epidemiologic studies show an increased risk of mortality among hepatitis C virus (HCV)-infected individuals compared with uninfected individuals from hepatic and nonhepatic causes. This article reviews the biologic plausibility of and epidemiologic evidence for the association between HCV and five extrahepatic malignancies: cholangiocarcinoma (CCA), pancreatic adenocarcinoma, papillary thyroid cancer, oral squamous cell cancer, and renal/kidney cancer. There is sufficient evidence to suggest that HCV is associated with intrahepatic CCA. The evidence for the link between HCV and pancreatic adenocarcinoma, oral squamous cell cancer, and renal/kidney cancer is compelling but requires further study. Based on available studies, there is no significant association between HCV, extrahepatic CCA, and papillary thyroid cancer.

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.

Evaluation of cellular proliferative activity in patients with oral lichen planus and hepatitis C through AgNOR method

The objective of this study was to evaluate the cellular proliferative potential of oral lichen planus (OLP) lesions from patients without hepatitis C virus (HCV) by means of AgNOR method, as well as the cellular proliferative potential of the normal oral mucosa from patients with HCV, treated or untreated by interferon and ribavirin. A cross-sectional study was developed to investigate four groups: 10 HCV+ patients without clinical signs of OLP who had never been treated for HCV infection - Group 1; 10 HCV+ patients that were under interferon and ribavirin treatment - Group 2; 15 patients with reticular OLP lesions histopathologically confirmed, without HCV - Group 3; and 15 blood donors without HCV infection and no clinical signs of OLP GROUP 4 Control Group. The cytological material of all groups was collected by the liquid-based cytology technique. Then, the sedimented material from each patient was filled with the Nucleolar Organizer Regions impregnation by silver method (AgNOR). The count of NORs was performed on 100 epithelial cell nuclei per patient using the Image Tool(tm) software. The Tukey HSD test was used to compare the median value of NORs among the groups and showed that the oral mucosa of HCV+ patients previously treated with anti-HCV drugs (GROUP 2), presented a higher average number of NORs in relation to others (p<0.05). The anti-HCV treatment may be related to increased cell proliferation of oral mucosa, indicating a possible relationship between OLP and HCV+ patients treated with interferon and ribavirin.

Association Between Hepatitis C Virus and Head and Neck Cancers

BACKGROUND

Hepatitis C virus (HCV) infection is associated with hepatocellular carcinoma and non-Hodgkin's lymphoma. In 2009, MD Anderson established the first US clinic for treating HCV-infected cancer patients, where we observed an unexpectedly large number of patients with head and neck cancers (HNCs). We sought to determine whether HCV is associated with HNCs.

METHODS

In this case-control study, medical records of cancer patients tested for HCV antibodies at our center from 2004 through 2014 were identified. Case subjects had new-onset primary oropharyngeal or nonoropharyngeal (oral cavity, nasopharynx, hypopharynx, or larynx) HNCs. Control subjects had smoking-associated (lung, esophagus, or urinary bladder) cancers. Biopsy reports of oropharyngeal cancers tested for human papillomavirus (HPV) were reviewed. Patients with lymphoma were excluded. Multivariable logistic regression models were constructed. All statistical tests were two-sided.

RESULTS

Of 34 545 cancer patients tested for HCV antibodies, 409 case subjects (164 oropharyngeal and 245 nonoropharyngeal) and 694 control subjects (378 lung, 168 esophagus, and 148 urinary bladder) were studied. The prevalence of HCV seropositivity was higher in oropharyngeal cancer patients (14.0%, 95% confidence interval [CI] = 8.7% to 19.4%, vs 6.5%, 95% CI = 4.6% to 8.3%), particularly HPV-positive oropharyngeal cancer patients (16.9%, 95% CI = 8.7% to 24.9%, vs 6.5%, 95% CI = 4.6% to 8.3%), and nonoropharyngeal HNC patients (20.0%, 95% CI = 14.9% to 25.0%, vs 6.5%, 95% CI = 4.6% to 8.3%) than in control subjects. Adjusted models showed a statistically significant association of HCV seropositivity with nonoropharyngeal (except nasopharyngeal) HNCs (odds ratio [OR] = 2.85, 95% CI = 1.38 to 5.88) and HPV-positive oropharyngeal cancers (OR = 2.97, 95% CI = 1.31 to 6.76).

CONCLUSIONS

HCV is associated with nonoropharyngeal (except nasopharyngeal) and HPV-positive oropharyngeal HNCs. Further studies are required to explore the possible interaction between HCV and HPV, and the association between HCV and other HPV-related malignancies.

Oral manifestations of hepatitis C virus infection

Extrahepatic manifestations (EHMs) of hepatitis C virus (HCV) infection can affect a variety of organ systems with significant morbidity and mortality. Some of the most frequently reported EHM of HCV infection, involve the oral region predominantly or exclusively. Oral lichen planus (OLP) is a chronic inflammatory condition that is potentially malignant and represents cell-mediated reaction to a variety of extrinsic antigens, altered self-antigens, or super antigens. Robust epidemiological evidence support the link between OLP and HCV. As the virus may replicate in the oral mucosa and attract HCV-specific T lymphocytes, HCV may be implicated in OLP pathogenesis. Sjögren syndrome (SjS) is an autoimmune exocrinopathy, characterized by dryness of the mouth and eyes and a multitude of other systemic signs and symptoms. SjS patients have also an increased risk of non-Hodgkin lymphoma. Patients with chronic hepatitis C do frequently have histological signs of Sjögren-like sialadenitis with mild or even absent clinical symptoms. However, it is still unclear if HCV may cause a disease mimicking SjS or it is directly responsible for the development of SjS in a specific subset of patients. Oral squamous cell carcinoma is the most common oral malignant tumour and at least in some part of the world could be linked to HCV.

Positive association between hepatitis C infection and oral cavity cancer: a nationwide population-based cohort study in Taiwan

OBJECTIVES

The association between viral hepatitis (B and C) and oral cavity cancer has been widely debated. This nationwide, population-based cohort study assessed the subsequent risk of oral cavity cancer among patients with chronic viral hepatitis infection.

MATERIALS AND METHODS

Data were retrieved from insurance claims data of 1,000,000 randomly sampled individuals covered under the Taiwan National Health Insurance system. We identified a total of 21,199 adults with chronic viral hepatitis infection (12,369 with HBV alone, 5,311 with HCV alone, and 3,519 with HBV/HCV dual infections) from 2000-2005. Comparison group comprised 84,796 sex- and age-matched subjects without viral hepatitis during the same study period. Incidence and risk of subsequent oral cavity cancer were measured until 2008.

RESULTS

The incidence of oral cavity cancers was 2.28-fold higher among patients with HCV alone than non-viral hepatitis group (6.15 versus 2.69 per 10,000 person-years). After adjusting for sociodemographic covariates, HCV alone was significantly associated with an increased risk for oral cavity cancer (hazard ratio (HR) = 1.90, 95% confidence interval (CI) = 1.20-3.02). This positive association was highest among individuals in the 40-49-year age group (HR = 2.57, 95% CI = 1.21-5.46). However, there were no significant associations between HBV alone or HBV/HCV dual infections and risk for oral cavity cancer.

CONCLUSION

Our data suggest that HCV but not HBV infection is a risk factor for oral cavity cancer. In addition, subjects with HCV infection tend to be at early onset risk for oral cavity cancer. This finding needs to be replicated in further studies.

Oral verrucous carcinoma arising from lichen planus and esophageal squamous cell carcinoma in a patient with hepatitis C virus-related liver cirrhosis-hyperinsulinemia and malignant transformation: A case report

Oral lichen planus (OLP) is a potentially malignant disorder associated with an increased risk of oral cancer. In Japan, the association of OLP with hepatitis C virus (HCV) infection is well documented. In the present study, a case of oral verrucous carcinoma arising from OLP coexisting vulvo-vaginal-gingival syndrome and esophageal squamous cell carcinoma (SCC) in a patient with HCV-related liver cirrhosis is reported. A 71-year old, non-smoking Japanese woman presented with lesions of OLP affecting the bilateral buccal mucosa, tongue, gingival, palate, oral floor and lower lip. Ten years later, an exophytic mass developed in the mandibular alveolar mucosa, the right buccal mucosa and the right lower lip. Pathological diagnosis confirmed the presence of verrucous carcinoma. However, she developed esophageal rather than oral cancer. The oral cancer was resected surgically three times and the patients underwent radiotherapy. The esophageal cancer was removed by endoscopic submucosal dissection. The risk of carcinogenesis increased as hyperinsulinemia continued. The results suggested that it is necessary to monitor for malignant changes in patients with OLP lesions and HCV infection. In addition, treatment requires the cooperation of various medical specialists, as well as an oral surgeon.

Oral lichen planus: controversies surrounding malignant transformation

Studies of the malignant potential of oral lichen planus (OLP) have been hampered by inconsistencies in the diagnostic criteria used for OLP, the criteria adopted to identify a true case of malignant transformation in OLP, the risk factors for malignant transformation and the optimum management of patients to ensure the early diagnosis of transformation. Consensus remains elusive, and leading workers in this field have recently published conflicting reports on the malignant potential of OLP and on the important question of the advisability of excluding patients with epithelial dysplasia or a tobacco habit from studies on this issue. The present review outlines these debates and proposes a possible a molecular basis for the malignant transformation in this disease.

Oral diseases associated with hepatitis C virus infection. Part 2: lichen planus and other diseases

Some of the most frequent extrahepatic manifestations of hepatitis C virus (HCV) infection involve the oral region predominantly or exclusively. Part 2 of this review discusses the current evidences regarding the association of lichen planus (LP) and other diseases frequently involving the oral cavity with HCV. Epidemiological data suggest that LP may be significantly associated with HCV infections especially in southern Europe and Japan but not in northern Europe. These geographical differences are possibly influenced by immunogenetic factors, the duration of the HCV infection and the design of the published studies. Because of the fact that most of the studies published are retrospective, it is impossible to establish whether the HCV exposure occurred earlier to or after the onset of disease and more prospective studies are clearly warranted. As the virus may replicate in the skin and oral mucosa and HCV-specific T lymphocytes can be found in the oral mucosa of patients with chronic hepatitis C and LP, HCV may be implicated in the pathogenesis of LP. However, little attention has been paid to the variable effect of therapy with interferon-alpha (IFN-alpha), with or without ribavirin for LP. Conversely, it is unlikely that other oral diseases such as oral carcinoma, pemphigus and Behcet disease are triggered by HCV.

Hepatitis C virus and lichen planus: A review

INTRODUCTION

The relationship between hepatitis C virus (HCV) infection and oral lichen planus (OLP) remains a matter of controversy. It is important to determine whether there is an association between OLP and HCV infection so that guidelines regarding the routine HCV testing of patients with OLP can be developed for clinicians.

OBJECTIVES

The objective of this article was to review and summarize the published literature on the association between OLP and HCV and to describe future directions.

METHODS

A search of the computerized database MEDLINE (1966-June 2003) was conducted. The bibliographies of articles identified by means of MEDLINE were also searched. Any studies reporting the prevalence of HCV in a group of patients with LP either with or without a control group were included in this review. Also included were studies comparing the clinical and histologic features of LP among patients with and without HCV infection, studies on the presence of HCV within LP lesions, and studies of HCV genotypes among patients with LP.

RESULTS

Thirty-two studies conducted in various parts of the world were identified. Study types included prevalence studies on HCV exposure among patients with OLP (0%-62%), prevalence of OLP among patients with HCV infection (1.6%-20%), and case-control studies of this association. In addition, the results from 3 studies on the replication of HCV in the oral mucosa, 3 studies on the genotype of HCV in OLP patients, and 4 studies comparing the clinical and histologic features of OLP in HCV-infected and uninfected individuals have been summarized.

CONCLUSION

At present, studies on the association of OLP and HCV provide enough information to raise a number of interesting questions about this association. Important biases-including selection bias; investigator bias due to lack of blinding and the possible resultant nondifferential misclassification of disease; and possible confounding by age in the studies published-make it difficult to draw firm conclusions. However, the need for future studies that take into consideration all these factors in the study methodology is highlighted by this review.

Risk of oral squamous cell carcinoma in 402 patients with oral lichen planus: a follow-up study in an Italian population

The most important complication of oral lichen planus (OLP) is the development of oral squamous cell carcinoma (OSCC) but this is a very controversial matter. The aim of the study was to estimate in a Northern Italian cohort of OLP patients the risk for OSCC. Four hundred and two patients with histologically confirmed OLP diagnosed from January 1988 to July 1999, were followed-up to the end of February 2001. The standardized incidence ratio (SIR) of OSCC was calculated for the entire cohort and specific for gender, type of OLP, therapy for OLP and hepatitis C virus (HCV) infection. The relative risk (RR) of OSCC according to HCV infection was also estimated in the cohort. During the follow-up period, two men (1.3%) and seven women (2.9%) developed an OSCC. The SIR was 44.9 (95% CI: 20.5-85.2), being higher among women, but statistically significant in both genders. The RR of OSCC for patients with HCV as compared with those without HCV infection was 3.16 (0.8-12.5). Patients with OLP had a significantly increased risk of OSCC, irrespective of the clinical type of OLP and therapy. HCV infection apparently increased the risk for OSCC although this result could reflect the role of confounders, such as liver cirrhosis.

Oral diseases possibly associated with hepatitis C virus

Morbidity associated with hepatitis C virus (HCV) infection can involve a variety of extrahepatic conditions, including lichen planus (LP) and sialadenitis, predominantly or exclusively involving the oral region, conditions which have been largely neglected in reviews. The literature suggests that HCV-infected patients may frequently have Sjögren-like sialadenitis with mild clinical symptoms, whereas oral LP may be significantly associated with HCV infections in Southern Europe and Japan but not in Northern Europe. These geographical differences could be related to immunogenetic factors such as the HLA-DR6 allele, significantly expressed in Italian patients with OLP and HCV. Analysis of experimental data suggests that HCV could be involved in the pathogenesis of both these diseases. Moreover, parotid lymphoma may arise in patients with sialadenitis, mainly with type II cryoglobulinemia. Little attention has been paid to oral health needs in HCV-infected patients and the variable effect of interferon-alpha therapy on oral tissues. Further research is needed, because of the potentially great influence of oral diseases possibly linked to HCV on the quality of life of millions of patients.

Lack of association between hepatitis C virus and oral epithelial dysplasia in British patients

Oral lichen planus may be a premalignant condition. An association between hepatitis C virus (HCV) infection and oral lichen planus has been described in Southern European and Japanese patients, and recently an association between HCV and oral squamous cell carcinoma was suggested from a study of Japanese patients. The present study investigated the frequency of chronic liver disease and HCV infection in UK patients with oral epithelial dysplasia (OED), a known premalignant disorder. Subjects included 75 patients with histologically proven OED and 110 healthy controls. Liver function and IgG antibodies to HCV were examined serologically. No patient with OED or control subject had serological evidence of hepatic disease, and anti-HCV antibodies were detected in only two (2.6%) of the 75 patients with OED, none of the controls being HCV seropositive. It is concluded that in the UK there is no association between HCV infection and OED.

Prevalence of hepatitis virus infection in association with oral diseases requiring surgery

OBJECTIVE

We evaluated the prevalence of hepatitis virus infection in a large population of patients in terms of diseases requiring oral surgery.

DESIGN

Retrospective case survey.

SUBJECTS AND METHODS

Prevalence of hepatitis B and C virus (HBV, HCV) infection were compared between oral diseases such as inflammation, cysts, cancer, trauma, benign tumors, impacted teeth, or jaw deformity in dental inpatients (n = 5830) with adjustment for age, gender, and history of surgery.

RESULTS

Of 4402 inpatients, 94 had HB surface(s) antigen (2.1%), while 151 of 2613 were seropositive for HCV (5.8%). Prevalences of HBs antigen and HCV antibody exceeded those in the general population. HBs antigen was more prevalent in patients with benign oral tumors than in patients with impacted teeth, whether or not adjustment was made for age (odds ratios, 4.246 and 5.055 with and without age adjustment, respectively; P < 0.05). On the other hand, HCV antibody was more prevalent in patients with oral cancer than in those with impacted teeth before adjustment for age (odds ratios, 2.433; P < 0.05), but this difference was reversed with age adjustment (odds ratios, 0.443; P < 0.05).

CONCLUSION

HBs antigen was more prevalent in patients with benign oral tumors, while HCV antibody was higher in patients with oral cancer. However, this increased incidence of HCV antibody apparently was a reflection of age. HCV infection may not have an etiologically important association with oral cancer.

Infectious hepatitis C, hepatitis G, and TT virus: review and implications for dentists

In the past 10 years, hepatitis C and G viruses have been identified, and in the last two years a further parenterally transmitted agent, termed TT virus (TTV), has been discovered. These viruses have a worldwide distribution and frequently cause chronic infection. The purpose of this article was to promote an understanding of these viral agents and their relevance in dental practice. Infected patients may develop a chronic carrier state without clinical disease or may develop liver disease, and may have related oral conditions. Dental providers will see a growing number of patients with HCV/HGV and possibly TTV infection. All of these patients require appropriate infection control measures during dental treatment.

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

On the basis of a literature review of the period 1950-1976, Krutchkoff et al questioned the possible premalignant nature of oral lichen planus. Their criticism was largely based on insufficiencies of data in support of the initial diagnoses of the condition. In this article, a review of the literature from the period 1977-1999 has been described; the criteria used were those of Krutchkoff et al. Thirty-three (34%) of 98 reported cases were accepted as having sufficiently documented evidence of malignant transformation of oral lichen planus. Although this percentage is somewhat higher than the percentage reported by Krutchkoff et al, there apparently remains a need for uniformly accepted criteria to establish a firm diagnosis of oral lichen planus. Only when such criteria are available will it be possible to conduct long-term prospective studies on the suggested possible premalignant nature of oral lichen planus.

The management of oral lichen planus

OBJECTIVE

To review the current literature regarding the medical treatment of oral lichen planus (OLP).

DATA SOURCES

PubMed on-line Medline data searches were carried out for the years 1966-1998 to identify reports on therapy of OLP.

METHODS OF STUDY SELECTION

Single case reports or open trials were included if they covered new therapeutic approaches or suggested significant modifications of known treatment modalities. Review papers were limited to those dealing with the topic.

DATA EXTRACTION AND SYNTHESIS

Every paper was critically examined. Because of the great heterogeneity of the response criteria, many data could not be directly compared. Stronger weight was given to therapies that have proven to be effective under placebo-controlled research protocols. Attention was also drawn to potential and effective adverse effects of every drug used.

CONCLUSIONS

Among the various medications advocated for the treatment of OLP, several lack conclusive findings from adequately controlled trials. Mainly high-potency topical corticosteroids in an adhesive medium appear at present the safest and most efficacious. Adjuvant agents as antimycotics may be useful in topical steroid treatment. Systemic corticosteroids may be occasionally indicated for severe recalcitrant erosive OLP or for diffuse mucocutaneous involvement. Topical cyclosporine should be considered in steroid-unresponsive cases considering that its efficacy in OLP could be related to a systemic effect and its high cost. Classical PUVA therapy seems to have too many side effects; topical application of psoralen is promising but still experimental. Topically and systemically delivered retinoids combined with topical corticosteroids could improve the efficacy of these agents whereas complete remission is difficult to achieve with retinoids alone and they frequently cause adverse effects. Finally, there are only few data concerning the long-term effect of the medical treatments upon the course of OLP and we do not know if therapy influences the malignant evolution of OLP.

The possible association between oral lichen planus and oral squamous cell carcinoma: a clinical evaluation on 14 cases and a review of the literature

Between 1986 and 1996, 263 patients, 156 females and 107 males, affected by oral lichen planus (OLP), were followed at the Division of Oral Medicine and Pathology, University of Naples 'Federico II', Italy, and at the Institute of Dentistry and Maxillofacial Surgery, University of Bari, Italy. During this follow-up, the possible association of OLP with oral squamous cell carcinoma (SCC), together with the possible association of OLP, oral SCC and chronic HCV-hepatitis, were investigated. 14 cases (5.32%) were known to have developed oral SCC: 10 (3.8%) in an area of pre-existing OLP, 3 (1.14%) in other sites, in 1 case the diagnosis of OLP and SCC was synchronous (0.38%). 3 patients were positive for anti-HCV antibody. Many carcinomas were in areas of reticular/plaque OLP. 3 patients had multiple simultaneous sites of oral involvement (21.42%); 5 patients developed oral SCC in different sites during the follow-up period (35.71%). These data, together with a clear histological evidence of progression to carcinoma within OLP lesions, suggest the probability of some cases of at least OLP having an intrinsic property predisposing to neoplastic transformation, confirming previous studies. For these reasons, the authors think that it is necessary to follow-up the patients regularly at least annually and possibly for life for the early diagnosis of a possible neoplastic degeneration. These consideration are particularly important in the case of atrophic or erosive OLP, and plaque OLP, especially when involving the dorsum of tongue.