Mutated and wild-type p53 expression and HPV integration in proliferative verrucous leukoplakia and oral squamous cell carcinoma

The frequencies of overexpression and mutation in the p53 tumor suppressor gene were examined in proliferative verrucous leukoplakia and oral squamous cell carcinoma with immunohistochemistry and single-strand conformation polymorphism analysis of DNA fragments amplified by polymerase chain reaction. Ten samples each of normal oral mucosa, proliferative verrucous leukoplakia, and squamous cell carcinoma were immunostained with antibodies against p53 protein; 8 of 10 cases of proliferative verrucous leukoplakia cases and 7 of 10 cases of oral squamous cell carcinoma were positive for p53 protein. Minimal staining was observed in normal oral tissues. The quantified labeling indexes demonstrated a range that corresponded to lesion progression. Single-strand conformation polymorphism analysis revealed p53 gene mutations within exons 5 to 8 in 40% (4 of 10) of the squamous cell carcinoma samples. Two of the 4 mutated squamous cell carcinoma samples lacked p53 expression. No p53 mutations were detected in proliferative verrucous leukoplakia tissues. Human papillomavirus 16 was identified in 2 of 7 p53 positive oral squamous cell carcinoma samples. Human papillomavirus 16 and 18 were identified in two of eight p53 positive proliferative verrucous leukoplakia samples. One p53 negative squamous cell carcinoma sample was positive for human papillomavirus 16 and had a mutation in exon 6 of the p53 gene. Human papillomavirus infection along with p53 expression plays a yet to be defined role in the pathogenesis of a limited number of cases of proliferative verrucous leukoplakia and squamous cell carcinoma. p53 Immunohistochemistry, p53 gene mutations, and human papillomavirus infection prevalence do not provide a means to differentiate between leukoplakia and carcinoma and do not provide a predictive test for progression of leukoplakia to carcinoma.     

Rapid progression of an idiopathic leukoplakia to a proliferative verrucous leukoplakia lesion and then squamous cell carcinoma

The article reports a case of oral proliferative verrucous leukoplakia (OPVL) in a 76-year-old woman, underscoring how an otherwise inconspicuous white plaque lesion can rapidly turn into a phase of verrucous carcinoma and subsequently squamous cell carcinoma.     

White, exophytic lesion of the left lateral surface of the tongue

Verrucous carcinoma is an unusual variant of squamous cell carcinoma; it comprises approximately 5% of all oral malignancies. The buccal mucosa, gingiva, and tongue are the most commonly involved areas within the oral cavity. Histologically, verrucous carcinoma can present a diagnostic dilemma. The basement membrane is often intact, which may cause the pathologist to misinterpret these carcinomas as hyperkeratosis and severe dysplasia. The preferred treatment for this lesion is wide local excision. Regional lymph node dissection is usually not necessary and radiation therapy appears to be contraindicated. Close follow-up is recommended.     

Proliferative verrucous leukoplakia; a critical appraisal of the diagnostic criteria

Since its introduction in the literature in 1985, the term proliferative verrucous leukoplakia (PVL) has been the subject of an ongoing discussion with regard to its definition. Widespread or multifocal occurrence of oral leukoplakia is not just synonymous to PVL. In the present treatise the proposal is made to require the involvement of more than two oral oral subsites, a total added seizeof the leukoplakic areas of at least 3 centimeters, and a well documented period of at least five years of disease evolution being characterized by spreading and the occurrence of one or more recurrences in a previously treated area. Key words:Oral premalignant lesions, leukoplakia, verrucous leukoplakia.     

Premalignant lesions of the oral mucosa. Prognosis, treatment and follow-up

To consider the value of prognostic factors in the development of a squamous cell carcinoma from a leukoplakia of the oral mucosa, a retrospective study was performed. Clinical and histological data of 104 patients with oral leukoplakia were analyzed. Leukoplastic lesions with dysplasia in the initial biopsy (n = 38) had been treated by excision (n = 28), by laser evaporation (n = 6) or a combination of these treatments (n = 4). Non-dysplastic lesions (n = 66) had been excised (n = 48), evaporised (n = 17) or treated by excision as well as laser evaporation (n = 1). During follow-up of maximal 6 years (mean 3.6 years), 12 patients had developed an infiltrative squamous cell carcinoma at the site of the primary lesion, 2 within a period of 24 months. No relation could be found between on the one hand size (p > 0.2), clinical aspect (p > 0.2), location (p > 0.45), and primary treatment (p > 0.15) of the lesion, and on the other hand the risk of developing a squamous cell carcinoma. Only a relation could be found between (the intensity of) dysplasia and the development of a squamous cell carcinoma (p < 0.001). It was concluded that because of the high risk of developing a squamous cell carcinoma, patients with a dysplastic mucosal oral lesion should be followed during a prolonged time.     

Detection of human papillomavirus-genomic DNA in oral epithelial dysplasias, oral smokeless tobacco-associated leukoplakias, and epithelial malignancies

Human papillomavirus (HPV) is an infectious agent that is increasingly associated with mucosal cancers, in particular cancer of the cervix. The present investigation was undertaken in an attempt to determine whether HPV could be easily detected in biopsies of oral tissues, specifically oral squamous cell carcinomas, oral epithelial dysplasias, smokeless tobacco keratoses, verrucous hyperplasia, and verrucous carcinoma. In situ DNA hybridization methods were used to isolate specific HPV genomes. Among 100 instances of benign leukoplakia, only 4% of non-tobacco-related and 10% of smokeless tobacco-related lesions harbored viral sequences. We were able to detect viral sequences in dysplastic lesions 3% of the time. Alternatively, 17% and 20% of the verrucous hyperplasias and verrucous carcinomas were positive for viral nucleic acids. Six percent of the squamous cell carcinomas harbored HPV. On the basis of these findings, it is concluded that HPV of known genotype can be identified in oral premalignant and malignant neoplasms.     

Expression of integrin α9 subunit and tenascin in oral leukoplakia, lichen planus, and squamous cell carcinoma

OBJECTIVES: Integrin alpha9 subunit is a member of beta1 integrin family and binds tenascin (TN). It is expressed by stratified squamous epithelium and may be associated with cell differentiation and growth. We studied if the expression of alpha9 integrin and TN is altered in leukoplakia, lichen planus, and squamous cell carcinoma (SCC).METHODS: Frozen sections of tissue samples obtained from normal human keratinized (16 subjects) and non-keratinized (three subjects) oral mucosa, oral leukopakias with dysplasia (19 subjects), reticular type lichen planus (nine subjects), or oral mucosal SCC (23 subjects) were stained immunohistochemically with antibodies against alpha9 integrin and TN.RESULTS: In contrast to its most prominent localization at the cell membranes of the basal epithelial cells in the normal mucosa, alpha9 integrin was localized in a more diffuse pattern with focal loss of expression at the epithelial cell membranes in leukoplakic dysplasia, lichen planus, and SCC. In some areas of SCC, alpha9 integrin localized throughout all cell layers of the tumor epithelium. In most areas, alpha9 integrin colocalized with TN but in heavily inflamed areas there was focal loss of TN and alpha9 integrin at the basement membrane zone. CONCLUSIONS: The findings show that alpha9 integrin expression is altered in leukoplakic dysplasia, lichen planus, and SCC.     

Proliferative verrucous leukoplakia: a case report

Proliferative verrucous leukoplakia (PVL) is a particularly aggressive form of oral leukoplakia that is resistant to treatment and presents a high risk of recurrence and malignant transformation. This article describes the microscopic and clinical characteristics of one case of PVL, which initially presented as hyperkeratosis with mild dysplasia and posteriorly developed multifocal areas and verrucous carcinoma despite treatment.     

Cytokeratin pattern of clinically intact and pathologically changed oral mucosa.

The various cytokeratin polypeptides in oral epithelia are expressed in dependence on site and formation of a stratum corneum. Certain cytokeratins occur permanently and others occasionally. In fibrous hyperplasia and Lichen ruber planus, patterns of cytokeratins did not deviate significantly from normal. In some but not all cases of squamous cell carcinoma and leukoplakia studied, marked aberrations of pattern were characterized by (i) appearance of cytokeratin No. 19, (ii) somewhat more frequent occurrence of cytokeratins Nos. 8 and 18, (iii) proteolytic modifications of cytokeratins, and (iv) partial loss of a few site-specific cytokeratins. The aberrations may be taken as additional diagnostic criteria for differentiation between non-aggressive and potentially aggressive leukoplakic lesion, even if they are not correlated with the conventional histological grading of dysplasia.     

Simultaneous PAGE, immunoblotting, and immunohistochemical analysis of differentiation associated keratins in lesions of the oral mucosa

The expression of differentiation associated high PM Keratin polypeptides of the oral mucosa lesions were studied by immunohistochemical and immunoblotting techniques applied to adjacent sections of each biopsy specimen. The material studied included specimens of leukoplakia, verrucous carcinoma, squamous cell carcinoma, adenocarcinoma and keratoacanthoma. Little or no expression of 65-67 Kd keratins was evident in squamous cell carcinoma and adenocarcinoma. Hyperkeratotic (both benign and dysplastic) lesions such as verrucous carcinoma, leukoplakia, and keratoacanthoma, showed great variations in the intensity of 65-67 bands and a very irregular immunohistochemical staining pattern. Increased amounts of horny substance was usually accompanied by absence of, or decreased expression of 65-67 Kd keratins, thus indicating a change in the polypeptide composition of the horny layer in pathological conditions of the oral epithelium.     

Painless verrucoid plaque on the lower lip

Verruca vulgaris is an uncommon oral lesion which is caused by an infectious agent, HPV. These growths have many clinical features in common with other oral lesions, the most serious of which are verrucous carcinoma and verrucoid squamous cell carcinoma. These various lesions can usually be separated on the basis of clinical and microscopic features. In some cases, however, immunohistochemical studies and DNA hybridization studies may be necessary before an exact diagnosis can be made.     

Proliferative verrucous leukoplakia of the gingiva

OBJECTIVE: The purpose of this study was to describe the clinical-pathologic features of what appears to be a gingival form of proliferative verrucous leukoplakia. STUDY DESIGN: Ten adult patients with recurrent and histologically progressive gingival leukoplakias who were diagnosed and treated at the University of California, San Francisco between 1994 and 1999, comprised the subject group for this investigation. Clinical and microscopic features were reviewed. Proliferation indices and p53 expression were evaluated immunohistochemically, and the presence of human papillomavirus (HPV) DNA was determined by using polymerase chain reaction (PCR) amplification. RESULTS: Lesions presented as solitary or regional flat/papillary/verrucal leukoplakias of the free and attached gingiva (tooth-bearing areas only). With time, flat lesions developed a papillary or verruciform profile. Although lesions were recurrent, they were confined to the gingiva, and multiple lesions did not develop. Half the patients used tobacco, and HPV could not be detected by using PCR. Microscopically, 6 cases began as hyperkeratotic lesions, and 4 initially exhibited a psoriasiform pattern with a marked inflammatory component. With recurrences, the lesions became progressively atypical histologically. The proliferation indices for these lesions showed modest increases over normal epithelium, and positive p53 staining was evident in 4 of 10 cases, indicating a disruption of the keratinocyte cell cycle in these lesions. The mechanism associated with the positive p53 staining (protein binding to wild type p53 versus mutation of the p53 gene) was not determined. Lesions recurred after conservative scalpel or laser excision, and many developed into verrucous or squamous cell carcinoma. CONCLUSIONS: Proliferative verrucous leukoplakia of the gingiva (PVLG) appears to be a subset of oral proliferative verrucous leukoplakia. It can be characterized as a solitary, recurring, progressive white patch that develops a verruciform architecture and may not be associated with HPV. PVLG has an unpredictable course and is at risk for development into verrucous or squamous cell carcinoma. Currently, there is no way to determine or predict which gingival white lesions will follow the clinical course described for this group of patients with PVLG.     

Bcl-2、MDM2和p21在口腔白斑和口腔鳞状细胞癌中的表达水平研究

目的：了解Bcl-2、MDM2、p21在人口腔正常黏膜、白斑、鳞状癌细胞中的表达情况.方法：采用免疫组化二步法检测15例人正常口腔黏膜、15例单纯增生性白斑、10例异常增生性白斑,25例口腔鳞癌中Bcl-2、MDM2和p21蛋白的表达情况.结果：Bcl-2、MDM2蛋白在异常增生性白斑和口腔鳞癌中的表达明显高于正常口腔黏膜上皮细胞;p21蛋白在异常增生性白斑和口腔鳞癌中的表达明显低于正常口腔黏膜上皮细胞.结论：Bcl-2、MDM2和p21三者与口腔黏膜癌变具有相关性.     

Proliferative verrucous leukoplakia: a clinicopathological comparative study

A retrospective clinicopathological analysis was performed to compare 35 proliferative verrucous leukoplakia (PVL), 40 leukoplakia without dysplasia (LK), 48 oral lichen planus (OLP)/oral lichenoid lesions (OLL), and 11 verrucous carcinoma (VC) (N = 134). The PVL group comprised 24 female and 11 male patients (mean age 66.5 years), with two to six sites involved (mean 3.1 sites) and multiple biopsies over time (mean 7.1/case). All PVL cases developed malignancy: 77.1% squamous cell and 40% verrucous carcinoma; 68.6% had multiple sites of malignancy. None showed local or distant metastatic spread. Five-year disease-specific survival was 88.6%. In LK and OLP/OLL, malignant transformation was significantly lower than in PVL (2.5% and 2.1%, respectively). Invasive squamous cell carcinoma was not reported in any conventional VC. Immunohistochemical histomorphometric analysis for p53, COX-2, and podoplanin showed no significant differences between the groups. PVL may overlap with LK, OLP/OLL, and VC, but has a persistent aggressive behaviour and high malignant transformation rate. The overlapping features may delay recognition as PVL. The results emphasize the need for a detailed clinicopathological definition of PVL, and long-term close monitoring to ensure progression to PVL and malignancy are recognized in time. The management of this persistent aggressive condition is challenging.     

Necrotizing sialometaplasia--a malignancy simulating oral lesion

A case of necrotizing sialometaplasia is reported in a 63-year-old white male. The lesion appeared as an ulcerated and painful lesion inside the left ramus mandibulae. An incisional biopsy was performed and reported as well-differentiated squamous cell carcinoma. A few days after the initial biopsy was taken the necrotizing tissue disappeared and the ulcer started to heal. A new, excisional biopsy was performed. The initial diagnosis was revised and the lesion reported as necrotizing sialometaplasia. Two weeks after the excisional biopsy complete healing was obtained. The clinical and histological findings are discussed in relation to the different stages through which a necrotizing sialometaplasia might develop. From a differential diagnostic point of view it is important for both the clinician and pathologist to be aware of the lesion's behaviour during the different stages of development.     

Surface roughness of squamous cell carcinoma of the oral mucosa

The surface roughness value of 39 oral squamous cell carcinomas was measured by the Rmax method. The means of the eight measurement values of each carcinoma ranged from 87 micron to 1176 micron. The average value of all 39 lesions was 341 micron. The average value of the lesions of the papillomatous and granulomatous types was larger than that of the leukoplakic and erosive types. The lesions with the size of more than 2 cm in diameter were rougher than those of less than 2 cm. The lesions of the gingiva were rougher than those on the tongue. There was an inclination that the surface of the verrucous carcinoma was rougher than that of the invasive squamous cell carcinoma and that the surface of early carcinoma was smoother than that of the invasive squamous cell carcinoma.     

TRAIL在口腔鳞状细胞癌和白斑中的表达及意义

目的：研究肿瘤坏死因子相关凋亡诱导配体（TNF-related apoptosis inducing ligand,TRAIL）在口腔鳞状细胞癌（OSCC）组织及白斑中的表达及意义。方法：采用免疫组化Maxvision两步法检测54例口腔鳞状细胞癌、30例口腔黏膜白斑、22例正常口腔黏膜组织中TRAIL的表达水平。结果：TRAIL在口腔鳞状细胞癌组织和黏膜白斑中的表达水平均低于其在正常口腔黏膜中的表达水平（P〈0.05）,分别为33.3%、56.7%、86.4%,其在癌组织与白斑中表达水平的差异无统计学意义。TRAIL在高分化癌组织中的表达水平高于中低分化组（P〈0.05）。TRAIL在不同临床分期组间及淋巴结转移与非转移组间表达水平的差异无统计学意义。结论：TRAIL表达的抑制可能与口腔鳞状细胞癌及口腔黏膜白斑的发生有关,并且TRAIL可能参与了初始阶段的正常黏膜向癌组织的转化。TRAIL在口腔鳞状细胞癌中的表达水平与癌组织的分化程度相关。     

重组人p53腺病毒注射液治疗口腔黏膜白斑的生物学反应观察

目的观察重组人p53腺病毒注射液Ad-p53治疗上皮异常增生型口腔白斑引起的生物学反应。方法对18例上皮异常增生型口腔白斑患者进行为期15 d的Ad-p53局部黏膜内注射治疗。每3 d注射1次,以1 cm2作为一个注射点,每点注射1×108 vp,0.5 mL。在最后一次注射后24~48 h内行病变组织活检,并用免疫组化法检测Ad-p53治疗前后组织内P53蛋白和P21CIP/WAF蛋白的表达。结果P53蛋白和P21CIP/WAF蛋白在Ad-p53治疗后组织内的阳性表达率分别为100%和89.9%,明显高于治疗前的表达,并且二者的高表达呈正相关（r＝0.598,P＜0.01）。结论Ad-p53治疗上皮异常增生型口腔白斑有良好的生物学反应,有广阔的临床应用前景。     

Proliferative verrucous leukoplakia: high incidence of gingival squamous cell carcinoma

BACKGROUND: Proliferative verrucous leukoplakia (PVL) is a multifocal and progressive lesion of the oral mucosa, often associated with papillomavirus, seen mainly in older females, and characterized by a high recurrence rate and high rate of transformation into verrucous or oral squamous cell carcinoma (OSCC). The aim of this study was to analyse the clinical characteristics of a substantial group of patients with PVL, evaluating the characteristics of those who developed cancer, and comparing them with a group of patients with OSCC but no preceding PVL. METHODS: A group of 30 patients with PVL was studied for the clinical aspects and characteristics, age, sex, location, recurrence, the appearance of new lesions, and the frequency of development of oral cancer. A disease control group was formed with 110 patients with OSCC chosen randomly from among those treated in the same Service in this period of time. The patients were grouped as PVL and no cancer (Group 1); PVL developing cancer (Group 2) and patients with OSCC without clinical lesions associated with PVL (Group 3). RESULTS: The average age of the PVL patients (Groups 1 and 2 combined) was 70.97 +/- 12.73 years, of which 80% were women. Only 23.3% were cigarette smokers. The area most frequently affected with PVL was the lower gingiva. Recurrence after treatment was seen in 86.7%, and new lesions appeared in 83.3%. Many (63.3%) developed cancer (Group 2). Comparison of Groups 2 and 3 patients showed that those with PVL developing cancer were more likely to develop gingival carcinoma and also to be older, more often females, and less likely to smoke tobacco. CONCLUSION: Cancer developing in patients with PVL manifested particularly on the gingiva.     

Short telomeres in an oral precancerous lesion: Q-FISH analysis of leukoplakia

J Oral Pathol Med (2012) 41 : 372–378 Objectives: A precancerous condition is a lesion that, if left untreated, leads to cancer or can be induced to become malignant. In the oral region, leukoplakia is a lesion that has been regarded as precancerous. In cases of oral carcinoma, we have frequently noticed that a type of leukoplakia histologically demonstrating hyper‐orthokeratosis and mild atypia (ortho‐keratotic dysplasia; OKD) is often associated with carcinoma, either synchronously or metachronously. Therefore, we consider OKD‐type leukoplakia to be a true precancerous lesion. Materials and Methods: In an attempt to clarify the relationship between OKD as a precancerous condition in the oral mucosa and telomere length, we estimated telomere lengths in this type of leukoplakia using quantitative fluorescence in situ hybridization, and also quantified the frequency of anaphase–telophase bridges (ATBs) in comparison with squamous cell carcinoma in situ (CIS) and the background tissues of CIS and OKD. Results: Ortho‐keratotic dysplasia was frequently associated with squamous cell carcinoma (45.0%) and showed significantly shorter telomeres than normal control epithelium, CIS, or the background of CIS or OKD. The frequency of ATBs was much higher in OKD than in control epithelium or CIS. Conclusion: Ortho‐keratotic dysplasia appears to be frequently associated with carcinoma, chromosomal instability, and excessively shortened telomeres, not only in the lesion itself but also in the surrounding background. Therefore, when this type of leukoplakia is recognized in the oral region, strict follow‐up for oral squamous cell carcinoma is necessary, focusing not only on the areas of leukoplakia, but also the surrounding background.