A computer-aided study on the tissue changes in oral keratoses and lichen planus, and an analysis of case groupings by subjective and objective criteria

Quantitative Exfoliative Cytology of Abnormal Oral Mucosal Smears

In this study quantitative techniques have been applied to smears collected from the buccal mucosa and floor of the mouth. The results display an encouraging success rate for identifying premalignant and malignant lesions. ‘Intrapatient’ normal smears provide a satisfactory control for comparison with pathological smears. Early results indicate that quantitative cytology could be of great value for monitoring and follow-up of suspicious lesions and provide an excellent additional diagnostic test for detecting early oral malignancy.

Computer aided morphometric analysis of oral leukoplakia and oral squamous cell carcinoma

We compared the changes in the cells in the basal layer of normal mucosa, oral leukoplakia with dysplasia and different grades of oral squamous cell carcinoma (OSCC) using computer aided image analysis of tissue sections. We investigated three morphometric parameters: nuclear area (NA), cell area (CA) and their ratio (NA:CA). NA and NA:CA ratio showed a statistically significant increase from dysplasia to increasing grades of OSCC. Nuclear size was useful for differentiating normal tissue, potentially malignant leukoplakia and OSCC.

An Insight to Oral Epithelial Dysplasia

Oral dysplasia is a potentially precancerous lesion diagnosed histologically. While the risk of progression is associated with histological grade, it is currently impossible to predict accurately which lesions will progress. Although most oral pathologists recognize and accept the criteria for grading epithelial dysplasia based on architectural and cytological changes, there can be considerable interexaminer and intraexaminer variation in the assessment of the presence or absence and the grade of oral epithelial dysplasia. This article reviews the alterations, criteria, different grading systems and the markers used for assessing the malignant transformation of epithelial dysplasia.

How to cite this article

Rastogi V, Puri N, Mishra S, Arora S, Kaur G, Yadav L. An Insight to Oral Epithelial Dysplasia. Int J Head Neck Surg 2013;4(2):74-82.

Reproducibility of grading systems in oral epithelial dysplasia

Objective: To assess inter and intra observer variability in grading oral epithelial dysplasia (OED) using Smith and Pindborg grading system, WHO classification system and Brothwell DJ et al. classification system. Study design: In the study 45 histological tissues of dysplasia, 15 each of mild, moderate and severe dysplasia were coded and blindly graded by three observers in three grading systems. Further on the same observers graded 15 slides again of the previous 45 for analyzing the reproducibility in the three grading systems. The individual significance of various indicators of dysplasia among various grades of dysplasia was also assessed. Result: Inter observer agreement was significantly higher in Brothwell system as compared to WHO and Smith and Pindborg system. Intra observer agreement was significantly higher in Smith and Pindborg system, but the predictability and the probability index was distributed over a larger range in this system. Each indicator of dysplasia was also found to be statistically significant (P<0.05) for grading dysplasia. Conclusion: The present study puts forth the inherent intricacies in the grading of oral premalignant lesions.

Key words:Carcinoma, dysplasia, grading systems, reproducibility.

Morphometry of the basal cell layer of oral leukoplakia and oral squamous cell carcinoma using computer-aided image analysis

Objectives:

To study and compare the changes in nuclear and cellular size, shape and nuclear–cytoplasmic ratio of the cells in the basal layer of oral leukoplakia and well-differentiated oral squamous cell carcinoma (SCC) with normal buccal mucosa, using computer-aided image analysis in tissue sections.

Study design:

This was a retrospective study conducted on tissue sections on a total number of 70 cases to determine the various morphometric parameters. The data collected in this study were analyzed statistically by computing descriptive statistics, viz., percentage, mean, standard deviation, standard error of mean, 95% confidence interval for mean. The difference in the control and study groups for various diagnostic variables was compared by means of analysis of variance (ANOVA), Student’s t-test for independent samples, wherever applicable. Mann–Whitney U-test and Kruskal–Wallis test were used where the data were found to be asymmetrical and the standard deviations were also different. The results were considered statistically significant whenever P ≤ 0.05.

Results:

Our results were significant for the morphometric parameter, size. The values of nuclear perimeter and area, cellular perimeter and area increased gradually from the normal buccal mucosa to leukoplakia, reaching the highest value in SCC. There was statistically significant difference in the nuclear and cellular areas to differentiate between leukoplakia and squamous cell carcinoma. Two variables which were used to study the shape, “form perimeter (PE)” and “contour index (CI)”, showed significant difference between normal buccal mucosa and leukoplakia and between normal buccal mucosa and SCC. The morphometric parameter, nuclear–cytoplasmic ratio, in our results showed an increase in leukoplakia and SCC compared to normal buccal mucosa, but the difference was not significant between leukoplakia and SCC.

Conclusion:

The morphometric parameter, size, was useful to differentiate between normal, potentially malignant leukoplakia and SCC.

Grading oral epithelial dysplasia: analysis of individual features

BACKGROUND

Assessing epithelial dysplasia to predict malignant transformation remains problematic in many tissues because grading systems are poorly structured and individual features poorly defined. Dysplasia grading is criticised for lack of reproducibility and poor predictive value. Grading systems for upper aerodigestive tract dysplasia have evolved over several decades and are not supported by good outcome experimental data.

METHODS

 This study analysed the individual features of dysplasia in 86 oral dysplastic lesions and determined the reproducibility of scoring for each, and correlated them with other features and clinical factors using complex clustering analyses.

RESULTS

A uniform pattern of dysplasia was found in 37 lesions, focal dysplasia in 36 and in 13 lesions dysplasia formed complex discontinuous patterns. There was wide variation in reproducibility of scoring of individual features and many, including thickness, some types of rete morphology, basaloid cell anisonucleosis, basal dyscohesion, and dyskeratosis as deep single cells correlated with sub-sites. Rete morphology, type of keratinisation, hyperchromatism of the basaloid compartment, prickle cell anisonucleosis and extension down salivary ducts correlated with smoking. Conventional grading and oral intraepithelial neoplasia (OIN) grading by 'thirds affected' showed strong correlation overall but scores obtained with the OIN system tended to a higher grade at all sites except soft palate/fauces. There was poor correlation between the systems for moderate dysplasia and also severe dysplasia at some sites. Individual features could not be shown to cluster to form distinct patterns of dysplasia.

CONCLUSIONS

These variations may account in part for the lack of reproducibility and poor predictive value of the grading systems in current use and could inform the design of future grading systems.

Computer vision approach to morphometric feature analysis of basal cell nuclei for evaluating malignant potentiality of oral submucous fibrosis

This research work presents a quantitative approach for analysis of histomorphometric features of the basal cell nuclei in respect to their size, shape and intensity of staining, from surface epithelium of Oral Submucous Fibrosis showing dysplasia (OSFD) to that of the Normal Oral Mucosa (NOM). For all biological activity, the basal cells of the surface epithelium form the proliferative compartment and therefore their morphometric changes will spell the intricate biological behavior pertaining to normal cellular functions as well as in premalignant and malignant status. In view of this, the changes in shape, size and intensity of staining of the nuclei in the basal cell layer of the NOM and OSFD have been studied. Geometric, Zernike moments and Fourier descriptor (FD) based as well as intensity based features are extracted for histomorphometric pattern analysis of the nuclei. All these features are statistically analyzed along with 3D visualization in order to discriminate the groups. Results showed increase in the dimensions (area and perimeter), shape parameters and decreasing mean nuclei intensity of the nuclei in OSFD in respect to NOM. Further, the selected features are fed to the Bayesian classifier to discriminate normal and OSFD. The morphometric and intensity features provide a good sensitivity of 100%, specificity of 98.53% and positive predicative accuracy of 97.35%. This comparative quantitative characterization of basal cell nuclei will be of immense help for oral onco-pathologists, researchers and clinicians to assess the biological behavior of OSFD, specially relating to their premalignant and malignant potentiality. As a future direction more extensive study involving more number of disease subjects is observed.

Decreased gene expression of human beta-defensin-1 in the development of squamous cell carcinoma of the oral cavity

The aim of this study was to investigate the gene expression of human beta-defensin-1, -2, -3 (hBD-1, -2, -3), interleukin-1beta, tumour necrosis factor-alpha and cyclooxygenase-2 in oral squamous cell carcinoma (OSCC) compared to benign and premalignant lesions as well as healthy controls. Biopsies of healthy gingiva (n=5), irritation fibroma (n=5), leukoplakia (n=5) and OSCC (n=5) were obtained during routine surgical procedures. RNA was extracted according to standard protocols and transcripts of hBD-1, -2, -3, interleukin-1beta, tumour necrosis factor-alpha and cyclooxygenase-2 were analysed by real-time polymerase chain reaction. The expression of hBD-1 was reduced in all lesions (5-fold in irritation fibroma and 2.5-fold in leukoplakia), but most significantly (50-fold) in OSCC. hBD-1 appears to play a role in the development of OSCC. The loss of its function might contribute to the malignant progression of these tumours.

Natural history of potentially malignant oral lesions and conditions: an overview of the literature

At a workshop coordinated by the WHO Collaborating Centre for Oral Cancer and Pre-cancer in the UK issues related to potentially malignant disorders of the oral cavity were discussed by an expert group. The consensus views of the Working Group are presented in a series of papers. In this report we review the literature on the epidemiology and natural history of potentially malignant disorders (PMD), detailing those characteristics of the patients and lesions thought to be associated with future development of oral squamous cell carcinoma (OSCC). Older patients, particularly females are more at risk than younger patients; the duration of PMD may be important. Those who have never used tobacco seem at greater risk than smokers. OSCC is more likely with PMD on the lateral and ventral tongue, floor of mouth and retromolar/soft palate complex than with those elsewhere. The vast majority of PMD in which OSCC develop are non-homogenous although 5% of homogenous PMD will develop carcinoma. Large lesions covering several intraoral subsites also appear more at risk.

Expression of RANTES and CCR1 in oral lichen planus and association with mast cell migration

BACKGROUND

T lymphocytes and mast cells infiltrate the lamina propria in oral lichen planus (OLP). Chemokines and their receptors are involved in T cell and mast cell migration and accumulation during the inflammatory process.

METHODS

In the present study, we investigated the role of RANTES and its receptors in OLP using immunohistochemistry, RT-PCR and an in vitro chemotaxis assay.

RESULTS

RANTES and CCR1 were expressed on T cells and mast cells in OLP, while OLP lesional T cell supernatants stimulated CCR1 mRNA expression in a human leukemia mast cell line (HMC-1). TNF-alpha stimulated CCR1, CCR4 and CCR5 mRNA expression in the same cell line. OLP lesional T cell supernatants stimulated HMC-1 migration, which was partly inhibited by anti-RANTES antibody.

CONCLUSIONS

The present study shows, for the first time, the distribution of RANTES and CCR1 in OLP. It is hypothesized that RANTES and CCR1 may play important roles in mast cell trafficking and related events in OLP.

Increased fractal complexity of the epithelial-connective tissue interface in the tongue of 4NQO-treated rats

The effect of the carcinogen 4-nitroquinoline 1-oxide (0.001% in drinking water) on the irregularity of the epithelial connective tissue interface (ECTI) of the ventral surface of the tongue was quantified in Dark Agouti and Wistar Furth rats. Histological tongue sections stained with the Azan-Mallory method were digitised (111 images, resolution 1 pixel = 3.1 microns), and the limit between epithelium and stroma of the ventral surface was extracted and analysed using a fractal geometry technique (local connected dimension). The results showed that although none of the images included carcinomas on the ventral surface of the tongue (all cases had other oral carcinomas), the epithelial profiles of the treated cases showed a statistically significant increase in irregularity when compared to controls. Canonical discriminant analysis of the parameters describing the irregularity of the ECTI classified 81.1% of the images in the original groups (treated or control). Fractal analysis is capable of detecting subtle architectural changes in the oral epithelium of the rat occurring after exposure to the carcinogen, even when full malignant transformation has not yet taken place. Fractal analysis, which may prove useful for monitoring the progression of carcinogenesis in this animal model, is a morphometrical parameter in the diagnosis of oral epithelial dysplasia.

Performance of a computer simulated neural network trained to categorise normal, premalignant and malignant oral smears

The accurate detection of malignant neoplasms whilst they are still small is recognised as one of the main factors increasing chances of survival. Neural networks have many biomedical applications and they have been applied to neoplasia but their use in oral pathology has only recently been documented. The objectives of this study were to train networks to discriminate between normal and dysplastic mucosa. Each network was trained by back propagation, internal cross validation and tested on additional data. The data were derived by analysing 348 intra-oral smears and included mean nuclear and mean cytoplasmic areas of the smears measured by image analysis. A neural network differentiated between normal/non-dysplastic mucosa and dysplastic/malignant mucosa (specificity 0.82, sensitivity 0.76). These early results suggest that integrating neural networks and image analysis, as well as investigating additional criteria, could enhance automation and accuracy of smear techniques in diagnosing oral malignancy.

How important is tumour shape? Quantification of the epithelial-connective tissue interface in oral lesions using local connected fractal dimension analysis

Quantification of the local complexity of the epithelial-connective tissue interface (ECTI) in normal mucosa, epithelial dysplasia, and squamous cell carcinoma of the floor of the mouth was investigated by estimating the local connected fractal dimension in tissue profiles from histological sections. The use of certain parameters of the distribution of the local connected fractal dimensions of the ECTI classifies the cases belonging to these three histopathological diagnoses with 85 per cent accuracy by means of linear discriminant analysis. The values of the local fractal dimension were also used to produce colour-coded dimensional images of the ECTI, to highlight locations with higher irregularity that may correlate with locally invasive 'higher-risk' areas.

Nuclear morphometry in squamous cell carcinoma (SCC) of the tongue

In the histological grading of oral squamous cell carcinoma (OSCC) nuclear features are very important. Nevertheless evaluation is usually performed in a subjective and not highly reproducible way. The aim of this work was to investigate the relationship between nuclear shape and survival in 30 cases of carcinoma of the tongue. All the patients were divided into two groups: short-term survival and long-term survival. Twenty nuclei for each tumour were submitted to a morphometrical study by the shape analytical morphometry (SAM) software system. It was thus possible to evaluate not only nuclear dimensions but also nuclear contour irregularities and nuclear shape asymmetries. Multivariate discriminant analysis (MDA) of the quantitative parameters obtained by the morphometrical study distinguished the patients of the two groups with only a 10% error; moreover successful cluster analysis was performed by using Fourier parameters. Both these sets of results were achieved mainly owing to the parameters for contour irregularities.

Intraexaminer and interexaminer reliability in the diagnosis of oral epithelial dysplasia

OBJECTIVES

Pathologists differ in their definition of "dysplasia." This study was done to test the hypothesis that experienced oral pathologists are consistent in diagnosing epithelial dysplasia.

STUDY DESIGN

Six board-certified oral pathologists examined 120 oral biopsies exhibiting simple hyperkeratosis to severe dysplasia. No clinical information was given, and presence of dysplasia was judged by histomorphology. Examiners' diagnoses were compared with sign-out diagnoses for each case. Months later, each examiner viewed 60 relabeled slides from the original 120. Each diagnosis was compared with the diagnosis in the first round.

RESULTS

Exact agreement with the sign-out diagnosis averaged 50.5% (within one histologic grade 90.4%). Examiners agreed exactly with their own diagnoses 50.8% of the time (within one histologic grade 92.4%). Agreement distinguishing dysplasia from no dysplasia compared with original sign-out diagnosis was 81.5%. Agreement with themselves distinguishing dysplasia from no dysplasia was 80.3%.

CONCLUSIONS

Accurate reproducible agreement among experienced board-certified oral pathologists diagnosing oral epithelial dysplasia is difficult to achieve.

Observer variability in the histologic assessment of oral premalignant lesions

Histopathologic examination of oral leukoplakias has a major impact on the assessment of prognosis and treatment planning. We investigated the extent of agreement in grading epithelial dysplasia between pathologists with the same or different educational backgrounds. Two general pathologists and two oral pathologists were each given 100 sections of oral leukoplakia to grade from no dysplasia to carcinoma in-situ. The interobserver agreement rates were in the range of 49% to 69%. The calculated kappa values were in the range of 27% to 45%, showing poor to moderate agreement between the pathologists. When comparing the kappa values between the two pairs of pathologists with the same education, these values did not diverge from the general level of kappa values, indicating that the interobserver variability was due to individual differences rather than to educational background.

Suppressor cell function in oral lichen planus

Oral lichen planus (OLP) is a common inflammatory condition of the oral mucous membranes which affects between one and two percent of the general population. In accordance with the protracted clinical course of OLP and its association with known auto-immune diseases, the level of self-tolerance is questionable and possibly diminished in patients with this disorder. Normal suppressor T lymphocyte function is reputedly an essential element in the maintenance of self-tolerance, and deficient cell-mediated suppressor activity is implicated in the pathogenesis of auto-immune diseases. For assessment of in vitro cell-mediated suppressor activity in OLP, peripheral blood mononuclear cells (PBMC) from ten patients with OLP and from 11 control subjects were activated with the plant mitogen concanavalin A (Con A), followed by co-culture with autologous responder cells. The ability of irradiated Con A-activated cells to suppress the proliferation of Con A-stimulated responder cells was determined. Con A-induced suppressor activity of PBMC in the OLP patients was significantly less than that in control subjects (p = 0.001). Results of the present investigation complement previous in vitro findings which provided indirect evidence of deficient cell-mediated suppressor activity in OLP, particularly a decreased proportion of circulating CD4+CD45RA+ lymphocytes and reduced Con A-stimulated PBMC proliferation. The depressed Con A-induced suppressor activity of PBMC in the OLP patients provides direct evidence of deficient in vitro cell-mediated suppressor function in OLP, and suggests that defective cell-mediated suppressor circuits and reduced self-tolerance may be involved in the pathogenesis of this disorder.

Histoquantitative study of inflamed tongue mucosa

A quantitative, semiautomatic analysis of histologic features of the specific inflammatory changes occurring on the dorsum of human tongue was made for 37 tongues. Well-documented histologic differences between clinically normal appearing tongue (control), atrophic, geographic and fissured tongue were shown quantitatively. The epithelium of atrophic tongue was thinner compared to the controls. Reduction of the thickness was due to the shortened or totally missing rete pegs. Epithelium of geographic and fissured tongue showed irregular rete pegs. In fissured tongue heavy inflammation seemed to shorten the rete pegs. In atrophic tongue the connective tissue was thicker compared to the controls. This could be due to mild, chronic inflammation causing loose connective tissue described in atrophic tongue. Muscle cells of geographic tongue appeared to be as in the controls, whereas in atrophic and fissured tongue the uppermost muscle cells were small and separated compared to the controls.

Aberrant glycosylation in oral malignant and premalignant lesions

Cell surface carbohydrates serve as differentiation and developmental markers characteristic of different cell and tissue types. The expression of these carbohydrate antigens is often significantly altered in tumors, particularly in those arising from epithelial tissues. Analysis of cell surface carbohydrates in oral epithelium have shown that in normal epithelium they are expressed in a way that shorter carbohydrates are found on basal cells and that these carbohydrate structures are elongated parallel to terminal differentiation. The carbohydrate expression is altered in oral carcinomas and in some oral premalignant lesions. The change in carbohydrate expression can at present be explained by the lack of synthesis of specific glycosyltransferases. We have found mosaicism in the expression of carbohydrate antigens in all tumors and have found that the expression of a specific carbohydrate in the deep invasive parts of the tumor correlates with tumor prognosis.

Morphometric analysis of suprabasal cells in oral white lesions

Surgical specimens from the cheek mucosa of 73 patients with white lesions were studied to determine various morphometric parameters that would help differentiate between the various types of oral mucosal white lesions that carry a risk of malignant change. Four cell types were represented: traumatic keratosis, leucoplakia, candidal leucoplakia and lichen planus, in addition to a control group of normal mucosa. The shape and size of the epithelial cells in two cell compartments, parabasal and spinous, were investigated by an interactive image analysis system (IBAS-1). The results showed an increase in the cell size in the parabasal cell compartment of all the white lesions compared with the normal mucosa. In the spinous cell compartment there was an increase in the cell size in lichen planus and traumatic keratosis; leucoplakia and candidal leucoplakia showed a slight decrease in cell size compared with the normal mucosa. Attempts to discriminate between the four groups of white lesions showed that these parameters can provide a high level of separation between lichen planus and the three other groups, but not between leucoplakia, candidal leucoplakia, and traumatic keratosis.

Effect of DMBA on oral cancer development in hamsters with latent HSV-1 infections in trigeminal ganglia

This study examined the effect of 7, 12-dimethyl-benz(a)anthracene (DMBA), polycyclic aromatic hydrocarbon carcinogen, on pathologic changes in buccal pouch mucosa of hamsters with latent herpes simplex virus type 1 (HSV-1) infections in their trigeminal ganglia. Of the pouches receiving DMBA treatment, the average number of tumors per pouch was significantly higher (p less than 0.01) in pouches of animals with HSV-1 infections as compared to those that received DMBA only. Of the pouches receiving DMBA, the average cumulative tumor diameter (the sum of the tumor diameters in each group divided by the number of pouches in that group) was notably greater in animals with latent HSV-1 than in animals that had not been infected; however, this difference was not significant. The DMBA-treated hamsters that had latent infections also displayed a higher severity and prevalence of histopathologic changes in their pouch mucosa. This study indicates that latent HSV-1 and DMBA show synergism in the development of tumors and precancerous histopathologic changes in hamster buccal pouch mucosa. An unexpected finding was that among the HSV-1 infected animals, 95% of the ganglia from animals treated with DMBA showed latent HSV-1 virus on explanation culture, whereas only 10% of the ganglia from infected animals that received mineral oil, rather than DMBA, contained latent virus.

Prediction of malignant transformation in oral epithelial lesions by image cytometry

The value of image analysis in predicting the malignant potential of oral epithelial lesions showing either hyperplasia or dysplasia was investigated; 5-micron formalin-fixed sections of 16 oral epithelial lesions, of which eight had later transformed to carcinoma and eight had not transformed during a follow-up of 10-15 years were studied. The sections were stained with the azure A-Feulgen reaction for nuclear DNA. In each section 200 nuclei of epithelial cells and 20 nuclei of lymphocytes were assessed; all measurements were made blindly. For each nucleus six features related to shape and amount of stain and six features related to chromatin pattern were assessed. For each feature the mean, SD, and interquartile range were determined and used for linear stepwise discriminant analysis. A model of three variables with the most discriminating power was developed. When the jackknifed classification test was applied using this model, the malignant potential of the lesions that later transformed could be predicted with 87.5% accuracy.

Course of various clinical forms of oral lichen planus. A prospective follow-up study of 611 patients

The course of reticular, papular, bullous, plaque-type, atrophic and ulcerative lesions of oral lichen planus (OLP) was studied in 611 patients. Mean age of the patients was 53 years and two-thirds were women. The patients were followed for periods from 1 to 26 years (mean, 7.5 years). The various clinical types had somewhat different courses. Papular affections were seen mainly in the initial phase and had a transitory course. Ulcerative lesions, although more persistent, also generally showed a short-term course. The atrophic form was fluctuating with many remissions and new-established affections. The plaque-type was a more constant form, but also demonstrated many newly established affections. After a few years, many patients had persistent lesions that no longer included the affections most characteristic of OLP, i.e. the reticular and the papular form. Initial presence of papular affections was associated with ages below 50 and atrophic lesions with ages above 60. Plaque-type affections were seen with a significantly higher frequency among tobacco smokers at the onset of OLP. No other correlation was found between the initial presence, the remission and the development of the different clinical forms and various factors as age, sex, general diseases, medication and tobacco smoking. Treatment with topical steroid and/or antimycotics had no effect on the long-term course of the various clinical forms, and it had no persistent effect on symptoms related to OLP. Complete remission was seen in 17% of the patients, and it showed a reverse association with the initial presence of plaque-type affections. However, complete remission was associated with an initial presence of papular affections.(ABSTRACT TRUNCATED AT 250 WORDS)

Malignant development of lichen planus-affected oral mucosa

The present report describes malignant development in oral lichen planus (OLP) among 611 patients (409 F, 202 M) followed for periods from 1-26 years (mean: 7.5). During follow-up, 9 patients (1.5%), 8 women (1.9%) and 1 man (0.5%) developed oral squamous cell carcinomas (SCC) in areas of lichen planus lesions. The age of the patients at diagnosis of carcinoma ranged from 56-79 years (mean: 70.4) and the length of follow-up before malignant development ranged from 4.9-24 years (mean: 10.1). The estimated number expected to develop oral cancer in a sample of the general Danish population of similar size, age distribution and follow-up was 0.18 (0.11 F, 0.07 M) i.e., OLP cases showed a 50-fold increase (F = 70- M = 14-fold). The observed number of cancer cases was significantly higher than the estimated number (p less than 0.00001). Therefore, oral lichen planus fulfils the WHO criterion of a premalignant condition.

Oncogenic potential of sexually transmitted viruses with special reference to oral cancer

Recent changes in social mores have been accompanied by a noted increase in the frequency of sexually transmitted diseases. Viruses that have been identified as causative agents for a large proportion of these diseases have also been associated with various malignant states. Concomitantly, the number of cases of oral cancer (considered to occur usually around or after the fifth decade of life) reportedly has been increasing among young adults. The oncogenic potential of several sexually transmitted viruses (HSV, HPV, CMV, and LAV/HTLV III) and their possible role in the development of malignant conditions, in particular oral cancer, are discussed in this review.

Morphometric analysis of basal cell layer in oral premalignant white lesions and squamous cell carcinoma

The size and shape of the cells in the basal cell layer of the oral epithelium in 100 specimens from oral mucosa were studied by using an interactive image analysis system (IBAS-1). Four groups of white lesions (traumatic keratosis, lichen planus, leucoplakia, and a "risk group") in addition to two control groups (normal mucosa and squamous cell carcinoma) were studied retrospectively. The results showed a progressive increase in the dimensions (area, perimeter, and maximum diameter) of the nuclei from normal mucosa through traumatic keratosis, lichen planus, leucoplakia and the "risk group" to carcinoma, with considerable differences. The nucleus in squamous cell carcinoma was twice as large as in normal mucosa. A substantial increase in the dimensions of both the cell and the nucleus was found in the "risk group." The nucleo:cytoplasmic ratio, contrary to what might have been anticipated in risk lesions, did not show considerable differences between the diagnostic groups. Furthermore, it was slightly decreased in the risk group compared with the normal mucosa. The shape factors (form PE and contour index) seemed to be less helpful in the identification of the "risk group." The size of the basal cell and its nucleus can be of diagnostic value for lesions with a high risk of malignant transformation.

Oral cancer induced in hamsters with herpes simplex infection and simulated snuff dipping

A number of epidemiologic studies indicate that snuff dipping is associated with an increased incidence of oral cancer in human beings. Since inactivated herpes simplex virus (HSV) has been shown to induce malignant changes in vitro and in vivo and is partially inactivated by snuff water extract, we examined the histopathologic changes of hamster buccal pouches after exposure to repeated HSV inoculation combined with long-term simulated snuff dipping. One hundred twenty-five Syrian hamsters were divided into seven groups, and the buccal pouches were inoculated with HSV-1, HSV-2, or culture medium. The mock and HSV inoculations were done once a month for 6 consecutive months. In an effort to determine the effect of snuff on the mock- or HSV-inoculated buccal pouches, a consistent amount of a commercially available snuff was placed into both the right and left pouches twice a day in half of the animals. At the end of the 6 months of simulated snuff dipping (4 weeks after the final mock or viral inoculation), the hamsters were killed and the buccal pouches were removed for the histopathologic evaluation. Neither simulated snuff dipping nor HSV infection alone induced neoplastic changes in hamster buccal pouches. However, HSV infection in combination with simulated snuff dipping resulted in epithelial dysplasia and invasive squamous cell carcinoma in more than 50% of the animals.

A semi-quantitative assessment of the histopathology of oral lichen planus

In a retrospective study of 112 cases, an attempt has been made to further delineate the histopathological parameters which are useful in making a diagnosis of oral lichen planus. The results of this study show that mononuclear infiltration beneath and adjacent to the epithelium, parakeratosis and degeneration of the basal layer of the epithelium were consistent features. Linear regression analyses of the parameters studied provided partial support for a cell-mediated immune mechanism.

Quantitative exfoliative cytology of normal oral squames: an age, site and sex-related survey

This study describes the development of quantitative cytological techniques and their application to oral smears. Nuclear and cell size has been measured and matched with age, sex and site in an attempt to produce a baseline for comparison with identical measurements carried out on pathological smears. The results displayed a significant variation in nuclear and cytoplasmic area between different sites. Nuclear size varied significantly with advancing age; however, this was not the case for cytoplasmic area. There was no significant variation in either criterion between males and females.

Epithelial dysplasia immediately adjacent to oral squamous cell carcinomas

A number of workers have attempted to identify dysplastic features which may be predictors of malignant change, by prospective studies of dysplastic lesions. In the present study we have looked at dysplastic changes immediately adjacent to established squamous carcinomas in an attempt to determine whether any predictors can be identified in this way. Eighty cases were included in the study for whom information on tobacco usage was known. Clinical details were recorded. Histological features in epithelium immediately adjacent to the carcinoma were studied in representative sections. Eighteen specific histological characteristics were noted as present or absent. Data were transferred by Conversational Monitoring System (CMS) terminal, processed and analyzed by the Statistical Analysis System (SAS) Computer package. Only 8 patients were non-smokers (10%). Dysplastic changes in adjacent epithelium were frequently multicentric. Changes appear to occur first in the basal layer in the form of disturbance of polarity or basal cell hyperplasia, while other dysplastic features are absent. The feature referred to as basal cell hyperplasia appears, in fact, to represent disturbed epithelial maturation. In 80% of cases increased nucleo-cytoplasmic ratio appears to result from a decrease in cytoplasmic volume rather than increased nuclear size. A defect in RNA synthesis may be a factor. A sharp decrease in inflammatory cells in the lamina propria of adjacent epithelium, compared with that of the carcinoma, was observed. Russell bodies were noted in 5 of the 8 lesions in non-smokers (63%) and in 16 of 72 lesions in smokers (22%) (p less than 0.001; Chi2 17.65).

An example of the use of quantitation in histological diagnosis by a comparison of normal human cheek mucosa and cheek mucosa affected by lichen planus

As an example of the use of quantitation in histological diagnosis the features of normal human cheek mucosa (NHCM) and non-ulcerative lichen planus of the cheek mucosa (LPCM) have been systematically studied and quantified in order to establish normal and pathological features which are constant. The technique enabled the quantitative verification of previously held concepts relating to NHCM and LPCM. A number of interesting features which have been given little attention in past literature were also noted. It is proposed that a reliable quantifiable range of characteristic histological features should be established for use in diagnosis where possible rather than relying on the subjective approach currently employed.

A differential diagnostic approach to the symptomatology of acute dental pain

Seventy-four patients with acute pulpitis, apical periodontitis, marginal periodontitis, or pulpoperiodontitis were examined. A series of symptoms and signs was registered. Diagnostic specificities and sensitivities were calculated, and thirteen variables were subjected to discriminant analysis and log-linear multiway contingency table analysis. Pulpoperiodonitis was found inseparable from pulpitis on the basis of the registered symptoms and signs. Several symptoms and signs previously believed to have differential diagnostic power were found insignificant. The following combination of symptoms and signs yielded a correct diagnosis in 82.1% of the cases: constant pain, tenderness to temperature changes, "the tooth feels extruded," impaired mouth opening, tenderness to palpation in apical area, and mobility.

Oral discoid lupus erythematosus. I. The validity of previous histopathologic diagnostic criteria

The histopathologic criteria set down by Lever for skin lesions of discoid lupus erythematosus (DLE) and the criteria for oral DLE suggested by the World Health Organization (WHO) have been tested on 136 biopsy specimens from oral lesions comprising 42 cases of clinically typical DLE, 24 cases of atypical DLE, 25 cases of lichen planus (LP), 25 cases of leukoplakia, 13 cases of indefinite diagnosis termed DLE? LP? and seven electrogalvanically- induced white lesions. Following studies of inter- and intraexaminer variation, the final recording was done in random order without the investigators knowing the clinical diagnosis in each case. The results showed that Lever's criteria had a high specificity for oral DLE as compared to LP and leukoplakia, but the sensitivity for clinically atypical oral DLE was rather low. The criteria established by the WHO showed no specificity for oral DLE as compared to LP. Neither the criteria by Lever nor the criteria of the WHO were specific for oral DLE as compared to electrogalvanically induced white lesions. Both sets contained criteria showing rather high inter- and intraexaminer variation. Therefore, there is a need to establish a set of histopathologic criteria showing high sensitivity and specificity for both clinically typical and atypical DLE, based on criteria showing a low inter- and intraexaminer variation.

Histometric study of leukoplakia, lichen planus and carcinoma in situ of oral mucosa

Leukoplakia, lichen planus and carcinoma in situ of human oral mucosa were analysed histometrically by light microscopy. Leukoplakia lesions showed a greater total nuclear density than lichen planus lesions. They had a similar basal nuclear density to carcinomas in situ. The total and basal nuclear areas were notably greater in carcinomas in situ, indicating the presence of larger nuclei in comparison to those of other lesions. We believe it to be possible to make a differential diagnosis based on numerical variables.

Oral leukoplakia and other white lesions of the oral mucosa related to dermatological disorders

"White lesions" of the oral mucosa often present problems of differential diagnosis, which are of primary importance when assessing precancerous changes in the mouth. The precancerous character of oral leukoplakia is well established, and the "high-risk" type: erosive-dysplastic leukoplakia of greater malignant potential, has been thoroughly investigated. Because of their possible association with oral carcinoma, some clinical types of oral lichen planus, namely, the atrophic erosive forms, indicate caution in their treatment and supervision. Epithelial dysplasia is often associated with candidiasis and discoid lupus erythematosus, but neither these, nor such other white lesions as white sponge naevus or morsicatio buccarum, are considered to be preneoplastic. All these white lesions may be clearly identified, differentiated, and circumscribed as clinico-pathological disease-entities, by clinical, histopathological and ultrastructural methods, thus facilitating early diagnosis, treatment and prevention of possible malignancy.

Distribution of ABO blood group substances in various types of oral lichen planus

Formalin-fixed, paraffin-embedded tissue sections of fifty oral lichen planus lesions including hypertrophic, atrophic and erosive types, were examined by an immunofluorescent technique for the presence of the ABO blood group antigens. The antigen activity in lichen planus lesions was compared with the reactivity of normal human and Rhesus monkey oral mucosa as controls, and the reactivity of adjacent normal epithelium in the same specimen. A difference in the distribution of the blood group substances was observed in the three different types of oral lichen planus. The hypertrophic showed the strongest staining reaction approaching that of the normal, whereas a decrease in quantity of blood group substances was seen in the atrophic, and a tendency to complete loss in the erosive type. There was a marked tendency for loss of staining to be greater in lesions from older patients; this could be related to the greater frequency of atrophic and erosive lesions in the elderly.

Correlative clinico-pathological evaluation of oral premalignancy

In 1972, the World Health Organization's "Meeting of Investigators on the Histological Definitions in Precancerous Lesions" defined a precancerous lesion as a "morphologically altered tissue in which cancer is more likely to occur than in its apparently normal counter part" (Pindborg 1980). There are two generally accepted precancerous lesions in the oral cavity, leukoplakia and erythroplakia (Pindborg 1980). Leukoplakia is currently defined as "a white patch or plaque that cannot be characterized clinically or pathologically as any other disease" (WHO 1978). This definition has no histological connotation and is used in a strictly clinical sense (Pindborg 1980, Banoczy 1977). Erythroplakia is defined as a "bright red velvety plaque which cannot be characterized clinically or pathologically as being due to any other condition" (Pindborg 1980).

Epithelial cells kinetics. A review of methods of study and their application to oral mucosa in health and disease. Part B. Comparison of cell kinetics in normal and abnormal epithelia

In Part A, the techniques most commonly used to study epithelial cell kinetics and their suitability for use in man are reviewed. In Part B, the application of such methods to comparative studies of normal and abnormal oral epithelial of both man and experimental animals is examined. Claims regarding the possible prognostic value of LI's or MI's of biopsies of potentially or overtly malignant human oral lesions are also considered. Normal and abnormal kinetic data for other lining epithelia, e.g., skin, uterine cervix and gastrointestinal mucosa are assessed where they provide a better illustration of some of the problems arising in such comparative investigations. Finally, the present and likely future areas in which cell kinetic studies may provide a guide to expected tumour prognosis and optimum treatment are summarized.

Computer analysis of the surface ultrastructural features of porcine oral mucosa

The surface features of histologically definable regions were recorded from standardized random scanning-electron micrographs. Computer-based discriminant and cluster statistical analyses were used to determine whether these surface features reflect only degrees of keratinization or are specific characteristics of each mucosal site. It was possible to distinguish consistently between keratinized and non-keratinized mucosa but, as a means of individual tissue identification, the analysis offered no advantages over conventional histological examination.

Variations in the nuclear-cytoplasmic ration during epithelial differentiation in experimental oral carcinogenesis

An increased nuclear-cytoplasmic ratio is one of the cytological features of epithelial atypia taken into account when the histopathologist subjectively assesses whether an epithelial lesion is likely to become malignant. The present work evaluates this ratio ultrastructurally in the DMBA-treated hamster cheek pouch model with a view to assessing whether alterations of this feature represent a valid indicator of malignant transformation. Following DMBA treatment, lesions obtained were assigned to three defined histopathological categories, namely epithelial hyperplasia, epithelial dysplasia and squamous cell carcinoma. Untreated pouches served as controls. Electron micrographs were obtained of basal, spinous and granular layer cells from each of these categories and the N/C ratio was evaluated using stereological point counting techniques. The results indicated that progressive decreases in the ratio occurred in all pathological stages during differentiation (i.e., between basal and granular cells). During carcinogenesis there was a tendency for the ratios to decrease in each cell layer but significant differences were not detected between normal and premalignant lesions.

Human buccal mucosa transplants in nude mice

The development of a model to study tissue interactions in human oral mucosa in vivo utilizing transplantation of human tissue to nude mice is described. Ninety-six samples of normal human buccal mucosa were transplanted to subcutaneous sites in the flank region of nude mice and were protected from overlying cutaneous and subcutaneous tissue by polyethylene capsules or by Millipore filters. Transplant recovery rates were 47% an 69%, respectively. The histologic features of the epithelium of transplanted specimens were compared to 20 biopsies of normal buccal mucosa. The epithelium of transplants maintained for 3 weeks or longer with either type of protection, maintained features essentially similar to the normal controls but was somewhat thinner.

The histopathologic features which follow repeated applications of tobacco tar to rat lip mucosa

The response of rat lip mucosa to two tobacco tar preparations combined with heat was examined histopathologically. It was shown that the magnitude of irritational hyperplasia produced was related to the level of irritation. This was greatest in those rats subjected to the longest period of application of the tobacco extract with the greatest concentration of tar combined with heating the site of application. Neoplastic changes were not produced.