Longitudinal study of TP53 mutations in eight patients with potentially malignant oral mucosal disorders

Objectives:  In a previous cross-sectional study, the authors found a higher rate of TP53 mutation in oral lichen planus (OLP) than in hyperkeratosis. By analysing for TP53 mutations in serial samples from patients on long-term follow-up of their oral lesions, it was hoped to determine if these mutations were related to disease progression.
Methods:  Eight patients presenting with lesions diagnosed clinically as oral leukoplakia or lichen planus were followed from 2 to 12 years. Two to five samples of archival biopsy tissue were analysed from each patient by constant denaturant gradient gel electrophoresis for hotspots A, B, C, D and exon 6.
Results:  Four patients were diagnosed clinically as OLP: two of these were confirmed histopathologically, one was diagnosed as non-specific hyperkeratosis and one as cancer. Four patients had leukoplakia only, with a histopathological diagnosis of hyperkeratosis. Seven patients had TP53 mutations, three of them on repeated occasions. All five patients who developed squamous-cell carcinoma had mutations. Two of them had mutated pre-malignant lesions, and one of these previously had a non-mutated cancer. Three patients had two different primary cancers, only one of them mutated. One patient developed a mutated cancer 5 years after the last mutation-free biopsy. Of the cancer-free patients, a lesion regarded clinically as cancer-suspicious in one case was mutated, in another patient two OLP lesions were mutated, the third had five biopsies taken during 8 years, all non-mutated.
Conclusions:  TP53 mutations may occur early or late in the development of oral squamous-cell carcinoma.     

Oral lichen planus has a high rate of TP53 mutations. A study of oral mucosa in icelanD

Oral squamous cell carcinoma (OSCC) is a world-wide health problem. In addition to external exposure (smoking and alcohol), certain oral lesions may increase the risk of oral cancer (e.g. leukoplakia, erythroplakia, and oral lichen planus). TP53 has been implicated in OSCC, but there are limited studies of mutations in premalignant oral lesions. In this study, 55 samples from OSCC, 47 from hyperkeratotic (HK) oral mucosa, clinically diagnosed as white patches, 48 samples from oral lichen planus (OLP), and 12 biopsies from normal oral mucosa were studied immunohistochemically for expression of TP53 protein. From all the carcinoma samples and selected non-malignant samples showing moderate or strong TP53 protein expression, malignant cells or TP53-positive nuclei were microdissected and screened for mutations in exons 5-8 by constant denaturation gel electrophoresis. Moderate to strong TP53 protein staining was seen in 56% of OSCC, 32% of OLP but only in 13% of HK. All OLP samples showed a characteristic pattern of positive nuclei confined to the basal layer, whereas TP53 staining was seen in suprabasal nuclei in HK. Mutation rate was 11 out of 52 for OSCC, three out of 20 tested for HK and, remarkably, nine out 27 tested for OLP. There was no correlation between TP53 protein staining and TP53 mutations. No associations were found with anatomical sites or disease progression. The unexpectedly high mutation rate of OLP might explain the premalignant potential of this lesion.     

光动力治疗口腔黏膜癌及癌前病变的临床进展

口腔癌是发生在口腔的恶性肿瘤之总称,严重影响人类生命和生活,发病率高,致残率和病死率高.许多口腔癌由癌前病变发展而来,最常见的是口腔黏膜白斑、扁平苔藓等.目前针对口腔癌一线治疗方案分为:手术切除、放射线治疗、化学治疗以及联合治疗.特别是高龄口腔癌症患者,传统治疗尚有一定的局限性和毒副作用.针对癌前病变常用药物和手术治疗...     

高危TP53突变与口腔鳞状细胞癌中淋巴结外侵犯的相关性分析

目的 探讨高危肿瘤蛋白53（tumor protein p53,TP53）突变与口腔鳞状细胞癌（oral squamous cell carcinoma,OSCC）淋巴结外侵犯（extracapsular spread,ECS）的相关性。方法 回顾性分析2013年1月—2016年1月甘肃省人民医院口腔颌面外科收治的88例OSCC患者资料。根据有无淋巴结转移分为无淋巴结转移组（A₁）、淋巴结转移不伴ECS组（A₂）、淋巴结转移伴ECS组（A₃）。比较各组TP53基因外显子（5-8）在原发灶及转移灶的缺失情况;ECS与无病生存率（disease-free survival,DFS）及总生存率（overall survival,OS）的相关性,TP53突变状态与ECS的相关性。采用SPSS 20.0软件包对数据进行统计学分析。结果 A₁组、A₂组及A₃组均发现TP53（5）纯合子缺失;A₃组（10/30）发现TP53（6）纯合子缺失;A₁组、A₂组及A₃组均未发现TP53（7）纯合子缺失;A₂组（7/42）、A₃组（10/30）及A₃组（10/60）发现TP53（8）纯合子缺失;A₁组1年和3年DFS分别为75.00%和70.83%,A₂组1年和3年DFS率分别为70.59%和58.82%,A₃组1年和3年DFS分别为46.67%和40.00%,A₃组1年和3年DFS显著低于其他2组（P<0.05）;A₁组1年和3年OS分别为83.33%和75.00%,A₂组1年和3年OS分别为73.53%和50.00%,A₃组1年和3年OS分别为46.67和40.00%,A₃组1年和3年OS显著低于其他2组（P<0.05）;A₃组发生TP53低危型突变（LR）4例（13.33%）,TP53高危型突变（HR）12例（40.00%）,TP53野生型突变（Wt）4例（13.33%）,其他突变10例（33.33%）。其中,HR型突变与其他突变较其他类型发生例数多（P<0.05）;吸烟、原发灶范围、野生型/低风险与高风险/其他与ECS存在相关性（P<0.05）。结论 OSCC患者中ECS是DFS与OS的重要标志物,且ECS中以高危突变较为常见,说明TP53高危突变与OSCC中ECS存在一定相关性。     

口腔扁平苔藓癌变潜能探讨——P53基因表达及形态计量学研究

目的从P53基因的表达及细胞形态计量变化,研究口腔扁平苔藓（OLP)癌变的潜能。方法采用免疫组化SABC法对28例OLP病损P53基因表达情况进行检测;用图像分析技术,对其中16例OLP的细胞形态学变化进行测量及分析,并分别与正常口腔粘膜、上皮异常增生性白斑、及鳞癌比较。结果P53蛋白在正常口腔粘膜中表达阴性,但可在OLP、白斑（LK）角朊细胞及鳞癌（SCC）癌细胞中表达,阳性细胞数比例由OLP、LK到SCC依次递增,差异有显著性（P＜0.05）。细胞形态定量结果显示OLP各项参数值介于正常与白斑和鳞癌之间,与鳞癌差异显著（P＜0.05）。结论OLP是一种界于正常及癌之间的良性病损,具有一定的恶变潜能,但恶变潜能可能低于白斑。     

The prevalence of oral mucosal lesions in a population in Ljubljana, Slovenia

The purpose of the present study was to evaluate the prevalence of oral mucosal lesions and conditions in a population in Ljubljana, capital of Slovenia. A total 1609 subjects represented the study population in the survey about the periodontal treatment needs in a population in Ljubljana, conducted from 1983 to 1987. Ten years later the same 1609 subjects were invited to the second examination. Altogether, 555 (34.5%) of the invited subjects in the age range 25-75 years came for an interview and clinical examination at the Department of Oral Medicine and Periodontology of the Dental Clinic in Ljubljana. Oral mucosal lesions and conditions were evaluated according to the WHO Guide to Epidemiology and Diagnosis of Oral Mucosal Diseases and Conditions. The results showed the presence of one or more mucosal lesions in 61.6% of the population. Fordyce's condition was observed the most frequently (49.7%) followed by: fissured tongue (21.1%), varices (16.2%), history of herpes labialis (16.0%), history of recurrent aphthae (9.7%), denture stomatitis (4.3%), leukoplakia (3.1%), cheek biting (2.7%), lichen planus (2.3%), frictional keratosis (2.2%), geographic tongue (2.2%), geographic and fissured tongue together (1.1%), mucocele (0.9%), smoker's palate (0.5%) and angular chelitis (0.4%). In the population examined, no oral malignancies were observed. Mucosal lesions like whitish lesions, denture related lesions, fissured tongue, varices and mucocele were more prevalent with increasing age. Tobacco-related lesions (leukoplakia and smoker's palate together) were significantly more prevalent among men than among women (P<0.05), while lichen planus, denture stomatitis and herpes labialis occurred more frequently in the female population.     

Prevalence and risk indicators of oral mucosal lesions in an urban population from South Brazil

Oral Diseases (2011) 17 , 171–179 Objective: The objective of the study was to assess the prevalence of oral mucosal lesions (OML) and to perform a multivariable risk assessment of demographic, socioeconomic, behavioral, and oral risk indicators for its occurrence in an urban population in South Brazil. Methods: This cross‐sectional study selected 1586 subjects (719M/867F, age: 14–104 years) using a multistage probability sampling strategy (65.1% response rate). Prevalence, odds ratios (OR), and confidence intervals (95% CI) were calculated accounting for the survey design. Results: Leukoplakia and lichen planus were observed in 1.01% and 1.02% of subjects, respectively. In the multivariable analysis, these lesions were significantly associated with moderate/heavy smoking (OR = 9.0, 95% CI = 2.1–39.1) and heavy drinking (OR = 2.0, 95% CI = 1.1–3.7). Candidiasis and proliferative lesions were observed in 14.09% and 3.80% of the subjects, respectively. These lesions were significantly associated with female gender (OR = 2.2, 95% CI = 1.5–3.2 and OR = 1.7, 95% CI = 1.0–2.8), older age (OR = 22, 95% CI = 8.0–60.8 and OR = 8.9, 95% CI = 3.4–23.7), and low socioeconomic status (OR = 1.9, 95% CI = 1.0–3.5 and OR = 3.0, 95% CI = 1.2–7.2). Conclusions: This population is in need of OML prevention and treatment. Future studies should validate the findings that premalignant lesions are causally related to smoking and alcohol consumption, and that other OML are associated with socioeconomic‐demographic disparities in this and similar populations.     

Potentially malignant epithelial oral lesions: discrepancies between clinical and histological diagnosis

OBJECTIVE: To evaluate the discrepancy index between the clinical and histological diagnosis and the prevalence of epithelial dysplasia and carcinoma in 45 patients with potentially malignant epithelial oral lesions (PMEL).PATIENTS AND METHODS: We submitted 45 patients with PMEL to clinical examination and obtained a biopsy from each. The results of histological diagnosis were compared to the clinical diagnosis.
RESULTS: Clinical diagnosis showed that the most common PMEL was leukoplakia followed by lichen planus and by actinic cheilitis associated with leukoplakia. The most common site was the buccal mucosa. Histological diagnosis revealed that 46.7% of the PMEL were lichen planus. The discrepancy index between clinical and histological diagnosis was 24.4%. The higher discrepancy index occurred among leukoplakias. The prevalence of epithelial dysplasia and carcinoma was 17.8%.
CONCLUSIONS: We conclude that all PMEL should be submitted to a microscopic analysis because the discrepancy between clinical and histological diagnosis was present in a quarter of these lesionS. Otherwise, the epithelial dysplasia and carcinoma were more frequent in the leukoplakias.     

Human papillomavirus infection in oral potentially malignant disorders and cancer

Human papillomavirus (HPV) infects keratinocytes in the mucosa or skin, and persistent infection with HPV may lead to premalignant lesions and invasive cancer, especially cervical cancer. It has also been hypothesized that HPV infection is an etiological factor of oral squamous cell carcinoma and oral precancerous disorders such as lichen planus, leukoplakia, and erythroplakia. A high percentage of HPV in oral lesions supports the possible viral contribution, but an association of HPV infection with these lesions remains to be established. The current paper will update the latest progress of HPV infection in several oral potentially malignant disorders and oral squamous cell carcinoma and discuss the impact of HPV infection on the progression of oral potentially malignant disorders.     

口腔白斑、扁平苔藓细胞凋亡相关蛋白Bax表达的研究

目的 :探讨口腔白斑、扁平苔藓的癌变机理及发病机制。方法 :采用免疫组化法检测 10例正常口腔黏膜上皮 ,18例扁平苔藓 ,2 3例白斑 ,2 2例口腔鳞癌上皮组织中凋亡相关蛋白Bax的表达水平。结果 :白斑中上皮单纯增生、轻度、中度不典型增生和低分化鳞癌及糜烂型扁平苔藓的Bax蛋白显过度表达 ,与正常口腔黏膜上皮相比有显著性差异。结论 :Bax参与了口腔白斑癌变的早期过程 ,Bax的表达水平可作为临床监测白斑癌变倾向的参考指标。扁平苔藓的发病机制可能与细胞免疫亢进刺激Bax过度表达诱导角朊细胞凋亡有关 ,扁平苔藓的癌变机理有待进一步研究     

Sequential immunohistochemical p53 expression in biopsies of oral lichen planus undergoing malignant evolution

Transformation in squamous cell carcinoma (SCC) may occur in a small percentage of patients affected by oral lichen planus (OLP), but the pathogenesis remains to be elucidated. Overexpression of p53 protein was investigated immunohistochemically in 28 cases of OLP, followed up by sequential biopsies for up to 96 months. In 15 cases (Group 1), no dysplastic changes or neoplastic transformation occurred during the follow-up period; in 7 cases, OLP and SCC were synchronously observed (Group 2), whereas in another 6 cases (Group 3) SCC developed several months or years after diagnosis of OLP. The percentage of p53-positive epithelial cells at first diagnosis was significantly higher in the cases of Groups 2 and 3 than in those of Group 1. In contrast, evaluation of growth fraction by MIB-1 monoclonal antibody did not show any statistical differences among the three groups. Although no conclusions can be drawn about the molecular pathway leading to neoplastic transformation of OLP, or about the role of p53, the results indicate that immunohistochemical evaluation of p53 expression may be a practical tool to select cases of OLP with a high risk of neoplastic transformation.     

P53蛋白在口腔鳞状细胞癌发生过程中的表达及意义

本研究采用微波处理暴露抗原,通过免疫组化ＬＳＡＢ方法对ＮＯＭ６例,ＯＰＬ２８例,ＯＳＣＣ３４例中Ｐ５３蛋白表达进行观察,其ＮＯＭ无表达;在ＯＰＬ中的表达率为８２％随着上皮异常增生的程度加重,表达率呈上升趋热（Ｐ〈０．０５）;而在ＯＳＣＣ中表达率为６５％,随着肿瘤的分极增加,表达率呈下降趋势（Ｐ〈０．０５）。结果表明,Ｐ５３蛋白在ＯＰＬ和ＯＳＣＣ中呈异常表达,并与ＯＰＬ程度和ＯＳＣＣ分级有关,Ｐ５３     

Prevalence study of oral mucosal lesions in a selected Cambodian population

Abstract The aim of this study was to investigate the epidemiology of oral mucosal lesions in a selected Cambodian population to obtain pilot data useful in planning an oral health data base for the country. Due to unstable conditions in Cambodia, the validity of population data related to present census information is highly questionable. Therefore, prior to this investigation a census registration was carried out using local health workers as registrars in nine villages of a commune. In the period July 4–31, 1991, a total of 1319 individuals (953 women, 366 men, 15–99 yr) were examined by one oral surgeon in the nine villages of Kok Trop Commune. Kandal Stung District, southwest of the capital Phnom Penh. Clinical diagnoses were based on WHO criteria. Information on smoking habits, betel nut chewing habits, and alcohol use was collected by 4 Khmer dental personnel. In total, 71 lesions were recorded in 64 (4.9%) individuals. Leukoplakia was found in 1.1%, lichen lesions in 1.8%, candidosis in 1.4%, submucous fibrosis in 0.2%, cancer in 0.1%) and other diagnoses in 0.8%. The prevalence of leukoplakia was 2.2% and 0.6% among men and women respectively, a statistically significant difference (P < 0.05). There were significantly more smokers (P < 0.01) among subjects with leukoplakia (64.3%) than among those without this lesion (28.6%). All subjects with lichen lesions were women. The age-adjusted relative risk for developing lichen among betel nut chewers as compared to non-chewers was 3.3. This study has provided information on epidemiological aspects of oral mucosal lesions, including the relationship to etiological factors such as tobacco smoking and betel nut chewing, which might prove valuable in planning future oral health studies and implementing preventive programmes in Cambodia.     

Interobserver reliability in the histopathologic diagnosis of oral pre-malignant and malignant lesions

BACKGROUND: The histologic classification of pre-cancerous and cancerous oral lesions has generally shown poor agreement between pathologists, but lesion and patient characteristics that may affect diagnostic reliability have not been explored. METHODS: Eighty-seven clinically suspicious oral lesions biopsied from 81 patients with previous upper aerodigestive tract cancer were independently classified by their local pathologist and a central pathology committee. Interobserver reliability between the local pathologist and the central pathology committee was measured with weighted kappa (kappa w) statistics and corresponding 95% confidence intervals (CI). RESULT: The kappa w for pathologic diagnosis was 0.59 (95% CI: 0.45, 0.72), and was higher for lesions without inflammation (0.67 (95% CI: 0.53, 0.80) than inflamed lesions (-0.10 (95% CI: -0.27, 0.07)). Greatest agreement was seen for lesions located in the buccal mucosa/vestibule (kappa w = 0.68 (95% CI: 0.46, 0.91)) and tongue (kappa w = 0.62 (95% CI: 0.40, 0.84)). Least agreement was found for lip/labial mucosa lesions (kappa w = -0.04 (95% CI: -0.34, 0.27)). Punch biopsies (kappa w = 0.67 (95% CI: 0.54, 0.80)) had greater interobserver reliability than wedge biopsies (kappa w = 0.38 (95% CI: 0.12, 0.64)). CONCLUSIONS: These data suggest that the presence of inflammation, lesion site, and biopsy technique modifies the reliability of oral lesion histologic diagnoses.     

Epstein–Barr virus prevalence in oral squamous cell cancer and in potentially malignant oral disorders in an eastern Hungarian population

We tested 65, 44, and 116 patients with oral squamous cell cancer (OSCC), oral leukoplakia (OL), and oral lichen planus (OLP) against 68 age-matched controls for the presence of Epstein–Barr virus (EBV). Apparently healthy mucosa was simultaneously sampled and examined in all patients. Paraffin-embedded tissue sections of all EBV-positive patients with OSCC were examined for latent membrane protein-1 (LMP-1) expression (demonstrable in most EBV-associated malignancies) using immunohistochemistry. The prevalence of EBV in the controls and in OSCC, OL, and OLP lesions was 19.1%, 73.8%, 29.5%, and 46.6%, respectively, and 66.2%, 22.7%, and 31.9% in the healthy mucosa of patients, respectively. The prevalence of EBV in OSCC patients was significantly higher than in controls or in respective samples of the other two patient groups both in the lesion and in the healthy mucosa. Comparisons including only patients with EBV-negative lesions yielded similar results. Lesions of patients with OLP, but not of patients with OL, differed significantly from controls in EBV prevalence. In OSCC, LMP-1 expression was not detected, and EBV carriage was not significantly associated with any risk factors and did not influence the outcome. Although a high prevalence of EBV was found in OSCC, comparable carriage rates on healthy mucosa of patients indicated that an aetiological role of EBV is unlikely.     

Value of epicutaneous patch testing in patients with oral, mucosal lesions of lichenoid character

The purpose of the present investigation was to determine, in patients with oral mucosal lesions of lichenoid character, whether it is possible with epicutaneous patch tests; to detect those who will react favorably to removal of amalgam. Of 48 patients, 19 (39.6%) showed positive patch test reactions to 1% mercury ammonium chloride, and 29 (60.4%) showed negative test results. The observation period varied from 3 months to 3 yr (mean value 1.5 yr). After treatment, 94.7% of the positive group and 86.2% of the negative group showed regression of lesions. Reactions exceeding the contact zone between amalgam restorations and lesions showed positive patch test results in 21% of the cases, as compared with 47% among those with lesions restricted to the contact areas; 85.7 and 93.9%, respectively, showed regression after removal of amalgam restorations. The results of the present study indicate that removal of amalgam usually affects the lesions favorably and that epicutaneous patch tests are of little prognostic value in patients with oral mucosal lesions of lichenoid character.     

Increased melatonin in oral mucosal tissue of oral lichen planus (OLP) patients: A possible link between melatonin and its role in oral mucosal inflammation

ObjectiveThe existence of extra-pineal melatonin has been observed in various tissues. No prior studies of melatonin in human oral mucosal tissue under the condition of chronic inflammation have been reported. The aim of this study was to investigate the presence of melatonin in oral mucosal tissue of patients with oral lichen planus (OLP) which was considered as a chronic inflammatory immune-mediated disease causing oral mucosal damage and ulcerations.Materials and methodsSections from formalin-fixed and paraffin-embedded oral mucosal tissue of OLP patients (n = 30), and control subjects (n = 30) were used in this study. Immunohistochemical staining was performed and the semiquantitative scoring system was used to assess the levels of arylalkylamine-N-acetyltransferase (AANAT: a rate-limiting enzyme in the biosynthesis pathway of melatonin), melatonin, and melatonin receptor 1 (MT1) in oral mucosa of OLP patients and normal oral mucosa of control subjects.ResultsAANAT, melatonin, and MT1were detected in oral mucosal tissue of OLP patients and control subjects. Immunostaining scores of AANAT, melatonin, and MT1 in oral mucosal tissue of OLP patients were significantly higher than those in control subjects (p = 0.002, p < 0.001, and p = 0.031, respectively).ConclusionsIncreased levels of AANAT, melatonin, and MT1 in the inflamed oral mucosal tissue of OLP patients imply that chronic inflammation may induce the local biosynthesis of melatonin via AANAT, and may enhance the action of melatonin via MT1.     

Progressive increase of human papillomavirus carriage rates in potentially malignant and malignant oral disorders with increasing malignant potential

Introduction:  We investigated the potential role of human papillomaviruses (HPVs) in potentially malignant oral disorders, oral leukoplakia (OL) and oral lichen planus (OLP), and in oral squamous cell cancer (OSCC) in an Eastern Hungarian population with a high incidence of OSCC.
Methods:  Excised tumor samples (65 OSCC patients) and exfoliated cells from potentially malignant lesions (from 44 and 119 patients with OL and OLP, respectively) as well as from healthy controls (72 individuals) were analysed. OLPs were classified based on clinical appearance, 61 patients had erosive–atrophic lesions (associated with higher malignancy risk, EA-OLP) and 58 had non-erosive non-atrophic lesions (with lower risk of becoming malignant, non-EA-OLP), respectively. Exfoliated cells collected from apparently healthy mucosa accompanied each lesion sample. HPV was detected by MY/GP polymerase chain reaction (PCR) and genotyped by restriction analysis of amplimers. Copy numbers in lesions were determined using real-time PCR. Prevalence rates, copy number distributions, and association with risk factors and diseases were analysed using chi-square test, t -test, and logistic regression, respectively.
Results:  We detected HPVs significantly more frequently in lesions than in controls ( P  ≤ 0.001 in all comparisons). HPV prevalence increased gradually with increasing severity of lesions (32.8, 40.9, and 47.7% in OLP, OL, and OSCC, respectively). Copy number distribution patterns roughly corresponded to prevalence rates, but OLP and OL were comparable. HPV prevalence differed significantly between EA-OLP and non-EA-OLP groups (42.6 vs. 22.4%); EA-OLP group showed a prevalence similar to that found in OL.
Conclusion:  HPVs may be involved in the development or progression of not only OSCC but also of potentially malignant oral lesions.     

A clinical study of 674 patients with oral lichen planus in China

BACKGROUND: Oral lichen planus (OLP) is a chronic inflammatory disease with different clinical presentations that can be classified as reticular, atrophic or erosive. Although OLP is a relatively common disorder, the reports comprising large numbers of OLP patients with specific character are lacking in the literature. The purpose of this paper was to describe the clinical characteristics of OLP in 674 Chinese patients. METHODS: A total of 674 charts of patients with histologically confirmed OLP were collected from Stomatological Hospital of Wuhan University between 1963 and 2003. RESULTS: Of the 674 patients, 65.9% were women and 34.1% were men. The most common clinical presentation was the reticular type (51.3%), and symptomatic OLP was noted in 67.5% of the patients, mainly in those with the erosive form. The erosive presentations showed significantly longer duration, more sites affected and a much greater old patients predominance than reticular or atrophic ones. About 90.9% of the patients had multiple oral sites of involvement and isolated lower lip lichen planus were observed in 60 cases (8.9%) and isolated gingiva lichen in only one case (0.2%). Skin involvement of lichen planus was found in 11.4% of patients. No statistically significant differences could be identified between OLP and diabetes, cardiovascular disease, smoking or alcohol use. Precipitating factors that resulted in an exacerbation of the disease were frequently noted and included foods, stress, dental cusp and poor oral hygiene. The transformation of OLP into malignancy was observed in four patients at sites previously diagnosed by clinical examination as erosive or atrophic lichen planus. CONCLUSIONS: Patients with OLP in China usually present with distinctive clinical morphology and characteristic distribution and few may display lesions with a confusing array of forms mimicking other diseases. A long time follow up is of utmost importance to detect its malignant transformation.