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

Stereological analysis of histological parameters in experimental premalignant hamster cheek pouch epithelium

Hamster cheek pouch mucosa was treated with the carcinogen DMBA in order to provide samples of epithelium in the various pathological stages of carcinogenesis. Stereological techniques were applied to histological sections of normal and carcinogen-treated epithelium in order to quantify cytological and tissue parameters that may be related to the features of epithelial atypia. The results were compared with values previously obtained for benign epithelial hyperplasia induced by a solution of oil of turpentine. Of the parameters investigated, the nuclear-cytoplasmic ratio, nuclear numerical density and volume-to-interface area ratios were best able to distinguish between benign and premalignant epithelium. The ability to ascribe actual numerical values to histological features which are usually only subjectively evaluated may be a useful diagnostic aid.

Changes in carbohydrate expression of lichen planus affected oral epithelial cell membranes

The purpose of the present study was to examine possible epithelial cell membrane changes in lichen planus affected oral mucosa by the use of the lectins concanavalin-A and ricinus communis agglutinin fraction I. It was shown that these lectins in contrast to what was found in normal epithelium do not bind to the cell membranes of basal cells of lichen planus affected epithelium. The lack of binding of lectins suggests changes in exposed carbohydrates at the surfaces of the cells. The findings may support the hypothesis of antigenic changes in the lichen planus affected epithelium.

Cellular hypersensitivity to oral lichen planus lesions in vitro

The purpose of the present investigation was to demonstrate in vitro cellular hypersensitivity to oral lichen planus lesions. Twenty oral lichen planus patients and 20 control persons matched by and sex were examined by the leukocyte migration agarose technique with tissue extracts from oral lichen planus lesions, normal oral mucosa and normal human kidney, the two latter extracts serving as control antigens. The female lichen planus patients showed statistically significant (P=0.004) migration inhibition with extracts from oral lichen planus lesions, which supports the hypothesis of cellular hypersensitivity to oral lichen planus lesions. However, the male lichen planus patients did not show any significant reaction. No significant reaction was found with the control antigens. The findings do not exclude the hypothesis of cellular hypersensitivity to oral lichen planus lesions. Furthermore, they do not support the hypothesis of oral lichen planus being an autoimmune disease.

Smoking habits of 611 patients with oral lichen planus

The smoking habits of 611 patients (68 per cent females and 32 per cent males) with oral lichen planus were studied. Forty-six per cent were daily smokers, 4 per cent smoked only at social events, and 50 per cent were nonsmokers. In comparison with the nonsmokers, the daily smokers showed significantly lower prevalences of reticular and atrophic types of oral lichen planus lesions and a significantly higher prevelance of the plaque type (P less than 0.001). It is suggested that these findings depend on a mechanism whereby original atrophic and reticular types of lesions are altered into the plaque type of lesions under the influence of smoking. The question arises whether such plaque type of lesion can be regarded as leukoplakias which have been superimposed on the oral mucosa affected by lichen planus.

Leukoplakia revisited. A clinicopathologic study 3256 oral leukoplakias

During a 13-year period, 3256 specimens clinically diagnosed as leukoplakia (('keratosis," "white patch") were submitted to the oral pathology laboratories of Indiana University School of Dentistry and Emory University School of Dentistry. These comprised 6.2% of the tissue specimens processed by these laboratories. The cases were analyzed as to age of occurrence, site of involvement, and pathologic findings. It was found that: leukoplakia occurs chiefly in the 5th, 6th, and 7th decades; about half of the lesions involved the mandibular mucosa, mandibular sulcus, and buccal mucosa; leukoplakia was slightly more common in men (54.2%). Microscopic study showed that 80.1% of the leukoplakias were varying combinations of hyperorthokeratosis, hyperparakeratosis, and acanthosis without evidence of epithelial dysplasia. Mild to moderate epithelial dysplasia was noted in 12.2% of specimens, and severe epithelial dysplasia or carcinoma in situ was found in 4.5%. Infiltrating squamous cell carcinoma was diagnosed in 3.1% of specimens submitted with a clinical diagnosis of leukoplakia. The risk of epithelial dysplasia, carcinoma in situ, or carcinoma varied between the anatomical locations of leukoplakia. The incidence of epithelial alteration, ranging from dysplasia to carcinoma, was 42.9% for lesions of the floor of the mouth, 24.2% for tongue lesions, and 24.0% for lip leukoplakias. The incidence of similar epithelial alterations in other sites varied from 18.8% for palatal lesions to 11.7% for leukoplakias of the retromolar area. The data suggest that there are regional differences in the incidence and character of leukoplakia in the United States. The Emory material, obtained almost exclusively from patients residing in the Southeastern United States, showed a proportionately higher total incidence, a lower male/female ratio, and a greater frequency of epithelial dysplasia, particularly in females, than the Indiana material, which came almost entirely from residents in the Northcentral United States.

Changing views on oral disease

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Further studies on lesions of the oral mucosa using computer-aided analyses of histological features

The histological feature of various "white lesions" of the oral mucosa have been subjected to computer-aided analyses, with the objectives of improving the accuracy of diagnosis, and the more reliable identification of the lesions most likely to progress to carcinoma.Previous reports on these studies have shown the potential usefulness of cluster and discriminant analyses, both for the classification of cases into their diagnostic groups, and for the identification of the tissue changes most useful in discriminating between one disease and another.The present report describes two extensions of this work. The first was the application of a scoring technique, based on discriminant analysis, to a new series of cases. In this series, the computer "correctly" identified 36 out of 41 that had been diagnosed as lichen planus by conventional methods. The second part of the study involved the calculation of the importance of each histological variable in defining the characteristics of groups of cases placed into different diagnostic groups or clusters by the computer. From these calculations, it was possible to depict the histological characteristics of each group in diagrammatic form.

Cell-mediated immunity and antibodies to Herpesvirus hominis type 1 in oral leukoplakia and carcinoma

Cell-mediated and humoral immune responses to Herpesvirus hominis type 1 (HVH1) and Candida albicans were studied in patients with leukoplakia, showing a histological spectrum of changes from epithelial keratosis to acanthosis and atypia, and in patients with carcinoma. The results were ranked according to increasing values of stimulation indices of lymphocyte transformation to HVH1, and the corresponding macrophage migration inhibition indices, and complement fixing antibody titres of each patient were correlated. This revealed that most patients with epithelial atypia were clustered to that end of the spectrum which had the highest stimulation and migration indices to HVH1; this relationship was not evident with C. albicans. In patients with keratosis and acanthosis there was a significant lack of correlation between lymphocyte transformation and migration inhibition to both HVH1 and C. albicans. In carcinoma the indices of lymphocyte transformation and migration inhibition to HVH1 and C. albicans were depressed. Furthermore, a significant negative correlation was found between lymphocyte transformation and migration inhibition to HVH1, unlike the positive correlation in control subjects. Complement fixing antibodies to HVH1, HVH2, cytomegalovirus and adenovirus, and fluorescent antibodies to C. albicans failed to show a significant change in titre in any one group of subjects tested. The results suggest a cell-mediated immune defect in leukoplakia, with a dissociation between lymphocyte transformation and macrophage migration inhibition to HVH1 and C. albicans in cases of keratosis or acanthosis. A specific increase in cell-mediated immunity to HVH1 in leukoplakia with epithelial atypia and the sequential changes argue in favour of a possible participation of HVH1 in carcinomatous transformation of some leukoplakias.

The use of discriminant analysis for examining the histological feathers of oral keratoses and lichen planus

In a retrospective survey of 235 cases in which the diagnosis on biopsy was lichen planus, keratosis or leukoplakia, the histological features were re-assessed as objectively as possible and without reference to the original diagnosis.The tissue changes were recorded under 39 headings, and many were assessed on a roughly quantitative basis. In addition, two clinical features were included; whether the biopsy was from the buccal mucosa (as opposed to some other intraoral site) and whether the lesions involved multiple intraoral sites. For each possible pair of diagnostic categories (keratosis and leukoplakia, lichen planus and keratosis, lichen planus and leukoplakia) the recorded findings were subjected to discriminant analysis in order to provide a quantitative assessment of the value of each individual feature for discriminating between the two diagnostic groups. The computer programme also provided for the application of these calculated values to yield a "score" for each case, and for an assessment of the significance of the separation of the diagnostic groups thus achieved. In general, the values calculated by the computer for the discriminatory value of each tissue change accorded with our subjective impressions, but a number of features that were given a relatively high value had not previously been recognized as important in differential diagnosisA discriminant analysis was also performed on those cases of leukoplakia known to have later developed a carcinoma, in comparison with the leukoplakia cases that did not develop carcinoma. High values were accorded mainly to the well-known features of epithelial atypia, but a similar high value was indicated for the presence of Russell bodies. we had not previously realized that the presence of Russell bodies was of prognostic significance in this context.When the total scores for the groups of cases were analysed, it was found that the separation of each pair of diagnostic groups was significant at the 1% level. The separation of leukoplakia cases that subsequently developed carcinoma, from those that did not develop carcinoma, was significant at the 5% level. In this latter analysis, a better separation might be achieved with larger numbers of cases, but there will always be the complicating factor that an unknown number of leukoplakia cases would develop carcinoma if the patient had received no treatment.