Observations on the clinical characteristics of oral lesions showing histologic epithelial dysplasia

Implications of Smokeless Tobacco Use Among Athletes

In brief: This literature review delineates the current status of smokeless tobacco. It discusses the prevalence and terminology as well as periodontal effects, buccal mucosal and soft-tissue alterations, leukoplakia, cancer, carcinogenic components, hemodynamic alterations, and potential addiction. It is clear that physicians and dentists should discourage their patients from using smokeless tobacco. Young people particularly may be influenced by popular sports figures and celebrities who convey the erroneous impression that smokeless tobacco is harmless.

CO2 laser surgery of oral premalignant lesions

Experiences gained in the CO2 laser treatment of patients with oral dysplastic precancerous lesions are presented. Besides 7 lichens planus, 50 leukoplakias of all grades of dysplasia, and carcinoma in situ and one lentigo maligna were removed superficially with a defocused laser. Within the average follow-up period of 37 months, 22% local recurrences were observed. In comparison with conservative drug therapy, conventional surgical procedures, and cryosurgical therapy, the CO2 laser treatment of multicentric premalignant diseases of the oral mucosa can be recommended as an alternative therapy.

Staining patterns of human pre-malignant oral epithelium and squamous cell carcinomas by monoclonal anti-keratin antibodies

Formalin-fixed, paraffin-embedded biopsies of metaplastic keratinized oral mucosa (fibromas and leukoplakias), oral mucosa with epithelial dysplasia and oral squamous cell carcinomas were stained with two monoclonal anti-keratin antibodies (AE1 and AE2). Intense suprabasal staining was seen with AE1 in metaplastic keratinized epithelium, whereas staining of adjacent normal unkeratinized epithelium generally was restricted to basal cells. In dysplastic epithelium and squamous cell carcinomas, staining with AE1 revealed a highly disturbed anti-keratin staining pattern. AE2 stained metaplastic keratinized epithelium in a suprabasal pattern but adjacent unkeratinized epithelium did not stain. In dysplastic epithelium and squamous cell carcinomas, AE2 staining was variable and sometimes absent. Further studies are indicated to clarify whether changes in anti-keratin staining patterns can be used for diagnostic and prognostic purposes.

Subjectivity in evaluating oral epithelial dysplasia, carcinoma in situ and initial carcinoma

During the 2nd Meeting of the International Association of Oral Pathologists in Amsterdam (1984), an exercise was held to study subjectivity in evaluating oral epithelial dysplasia. A poster with 9 color photomicrographs was presented to be evaluated anonymously by the participants. A total of 72 submitted diagnostic suggestions. In Table 1 these suggestions are given together with the diagnosis by the authors. A surprisingly wide spectrum of diagnostic suggestions was found indicating the need for an internationally accepted set of criteria for oral epithelial dysplasia.

Proliferative verrucous leukoplakia. A long-term study of thirty patients

Up to 6% of oral leukoplakia, a relatively common mucosal disease, can be expected to become malignant. This report describes a long-term study of 30 patients in whom a particular form of leukoplakia was identified and labeled proliferative verrucous leukoplakia (PVL), a disease of unknown origin, which exhibits a strong tendency to develop areas of carcinoma. PVL begins as a simple hyperkeratosis but tends to spread and become multifocal. PVL is slow-growing, persistent, and irreversible, and in time areas become exophytic, wartlike, and apparently resistant to all forms of therapy as recurrence is the rule. The disease was most commonly seen in elderly women and had been present for many years. Patients were followed for 1 to 20 years. Thirteen died of or with their disease, 14 were alive with PVL, and 3 were alive without PVL at last contact. PVL rarely regressed despite therapy. All patients who died had persistent or recurrent disease. PVL appears to constitute a continuum of hyperkeratotic disease, ranging from a simple hyperkeratosis at one end to invasive squamous cell carcinoma at the other. Microscopic findings are dependent upon the stage of the disease's development and the location and adequacy of the biopsy.

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).

A critical evaluation of epithelial dysplasia in oral mucosal lesions using the Smith-Pindborg method of standardization

Standardization is one of the greatest problems in assessing epithelial dysplasia, as is establishing the relative importance of different clinical and dysplastic features. In this study, 214 cases characterized histologically by varying degrees of epithelial dysplasia, were analyzed for various clinical features: and representative sections were assessed histologically and graded according to the Smith-Pindborg standardized scoring system. Data were analyzed by computer. Seven cases with scores of less than 10 were excluded as not dysplastic. There were 85 cases (41%) with scores of 11-25 which were regarded as mild dysplasia; 60 (29%) with scores of 26-45 were regarded as moderate dysplasia; and 62 (30%) with scores of more than 45 which were reported as severe dysplasia. Peak frequency was in the 6th decade and the severe dysplasias were most frequent in the 8th decade. The M:F was 2:1. Tongue (58 cases), lower lip (36), floor of mouth (32) and cheeks (26) were sites most commonly involved. Of 107 cases, 93 were described as homogeneous leukoplakia, 11 as speckled leukoplakia and 3 as erythroplakia. The distribution of mild, moderate and severe dysplasias did not differ significantly by age, sex or race. Half of all cases involving floor of mouth and oropharynx were severely dysplastic, whereas most lesions occurring in cheek and alveolar mucosa/gingiva were mildly dysplastic; but differences were not significantly different. Severe grades of each dysplastic feature, as might be expected, occurred in lesions classified finally as 'severe dysplasia'.(ABSTRACT TRUNCATED AT 250 WORDS)

Gamma-glutamyl transpeptidase in precancerous lesions and carcinomas of oral, pharyngeal, and laryngeal mucosa

This study was undertaken to determine whether gamma-glutamyl transpeptidase (GGT) histochemical activity is expressed during the development of human oral, pharyngeal, and laryngeal squamous neoplasms. Surgical specimens from 46 patients were sampled and unfixed frozen sections were prepared and processed for histopathologic evaluation and histochemical localization of GGT. The patients' tobacco exposure, alcohol intake, and previously diagnosed neoplastic disease were documented. Generalized or patchy GGT histochemical activity was observed in each of 22 squamous cell carcinomas and in each of 33 dysplastic samples. Thus, GGT appears to be expressed during the development of malignant squamous epithelial neoplasms of the oral-pharyngeal-laryngeal region. In addition, the detection of GGT activity in several samples of nondysplastic epithelium, obtained from patients at high risk of developing cancer in this region, raises the possibility that this marker is expressed in very early precancerous sites that have not yet developed the histologic hallmarks of premalignancy.

Oral leukoplakia and malignant transformation. A follow-up study of 257 patients

Two hundred fifty-seven patients with oral leukoplakia were studied and followed for an average period of 7.2 years. All lesions were more than one cm in size and had been present and observed for a minimum of 6 months. Of the initial biopsies, 235 revealed a benign hyperkeratosis and 22 others contained some degree of epithelial dysplasia. Seventy-three percent of the patients used tobacco, with cigarette usage being the predominant form. Forty-five patients (17.5%) subsequently developed squamous carcinomas in the hyperkeratotic epithelial site in an average time of 8.1 years. Eight of these malignant transformations came from patients who originally had epithelial dysplasia. High risks for malignant transformation also included non-smoking patients, the clinical presence of erythroplasia (erythroleukoplakia), and a clinical verrucous-papillary hyperkeratotic pattern. Duration of the leukoplakia progressively increased the total number of malignant transformations, with the largest rate occurring in the second year. This study confirms that oral leukoplakia is a precancerous lesion and that certain characteristics indicate greater risks and warrant consideration of more aggressive management.

Carcinogenesis in forestomach and changes in oral mucosa of rats induced by intragastric N-methylnitrosourea

It is well known that oral administration of N-methylnitrosourea (NMU) induces carcinomas in the forestomach of experimental animals. As the rat forestomach is lined with an orthokeratinized squamous epithelium the purpose of the present study was to elucidate whether carcinogenesis in this localization following intragastric application of NMU was comparable to oral carcinogenesis in experimental animals and humans. Furthermore, the development of oral mucosal lesions in the rats was studied. It is concluded that the morphologic changes seen during carcinogenesis in the forestomach do not seem to differ essentially from those seen during experimental and human oral carcinogenesis. Furthermore, the number of oral lesions found in the present study are higher than reported in other strains of rats following administration of NMU.

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).

Transformation of oral lichen planus to squamous cell carcinoma: a literature review and report of case

We have presented a case of malignant transformation of oral lichen planus along with a review of the literature and a brief description of the disease. We have attempted to indicate that within defined terms, oral lichen planus should be considered a pre-malignant lesion in which incidence of transformation approaches that of clinical oral leukoplakia, yet is clearly distinctive from that disease with regard to age and sex distribution. The erosive form of oral lichen planus most often precedes carcinomatous change. A protocol is described for documentation and periodic follow-up procedures for such patients to possibly intercept a developing malignancy.

Experimental induction of irreversible precancerous changes in the palatal epithelium of the rat

The development of irreversible precancerous changes in the palatal mucosa of the rat was studied macroscopically and histologically after painting the palate 3 times a week with 0.5% 4-nitroquinoline-N-oxide for 1-22 weeks. Control animals were painted with the solvent propylene glycol. After the application periods, the spontaneous development of premalignant epithelial changes and carcinomas was recorded by repeated biopsy procedures. Short application periods (1-6 weeks) were consistently followed by prolonged expectancy periods (51-80 weeks) before the development of carcinomas. Comparably long application periods (more than 12 weeks), however, induced carcinomas after relatively short expectancy periods (8-21 weeks). The total experimental periods (application plus expectancy periods) for animals painted for more than 12 weeks were frequently less than 1/2 of that for animals painted for 1-6 weeks. All experimentally induced tumours represented highly differentiated squamous cell carcinomas with excessive keratin formation. They were consistently preceded by different stages of epithelial dysplasia. Advanced carcinomatous changes were frequently not visible macroscopically. Irreversible precancerous transformation had already occurred in epithelium at early hyperplastic, non-dysplastic stages.

Panoral verrucous dysplasia. Report of a case treated with split-thickness skin graft

The treatment of panoral verrucous dysplasia involving the maxillary edentulous alveolar ridge, buccal vestibule, and palate is discussed. A case is presented in which a maxillary vestibuloplasty and skin graft were employed in treatment.

The clinical and histopathologic features of a series of 464 oral squamous cell papillomas

A clinical and histopathologic analysis of 464 oral squamous cell papillomas is presented. Data on age, sex, race, location, clinical appearance, duration, recurrence, and clinical diagnosis are reviewed. One hundred seventy-six of the 464 specimens were examined for hyperkeratosis, character and amount of inflammatory infiltrate, and evidence of cellular atypia. The trends seen in this study support claims made by previous authors regarding incidence and inflammatory involvement. The data support a slightly higher occurrence rate in males than in females and in white as opposed to black patients. Papillomas were most abundant on the palatal complex, dorsum and lateral tongue borders, and lower lips, respectively. Confusion of papilloma for fibroma in the clinical diagnosis was less common than expected. Recurrence rate and incidence of multiple papillomas were low. Histologic study revealed a tendency for hyperkeratotic lesions to arise from nonkeratinized oral sites. Cellular atypia was found, but it is still unclear whether these changes are preneoplastic or due to an increased growth rate.

Clinical, histological and ultrastructural features of a possibly virus-induced oral leukoplakia

Two male patients with oral leukoplakias exhibiting a peculiar type of apparent dysplastic changes have been followed for 4 and 6 years, and a series of biopsies have been examined by light and electron microscopy. The apparent lack of normal epithelial stratification below the keratinized cell layers was mainly caused by the frequent appearance of large ballooned cells and multinuclear giant cells. The centre of the large ballooned cells contained aggregations of chromatin and evenly-dispersed microtubulus surrounded by a thick rim of tonofibril bundles. In the peripheral cytoplasm large numbers of smooth-surfaced endoplasmic reticulum were found, but no Golgi apparatus was observed. In addition, several autophagocytic bodies were recorded. Along the cell membrane only a few desmosomes were present, whereas aggregations of digested desmosomes were found in the cytoplasm. On the basis of the ultrastructural findings, it is suggested that the large ballooned cells represented epithelial cells arrested in early stages of mitotic division. The epithelial cells in interphase exhibited a normal ultrastructure except for large nucleoli with varying degrees of condensation of nucleolonema and vacuolization. Further, atypical dense granular aggregations and strands of fine fibrillar material were recorded in the nuclei. It is suggested that this new type of oral leukoplakia has a viral etiology.

A follow-up study of sixty-one oral dysplastic precancerous lesions in Indian villagers

In a 7-year follow-up study of 107 cases of oral epithelial dysplastic precancerous lesions in Indian villagers, 6.6 per cent were found to develop into carcinomas. A clinical spontaneous regression occurred in 14.8 per cent. Follow-up biopsies showed histologic regression of dysplasia in six cases.

Follow-up studies in oral leukoplakia

Follow-up examinations of 670 patients with oral leukoplakia during a 30-year-period showed cancer development in 40 cases, i.e. 6%. Dysplasia was observed in 24% of the histologically examined leukoplakia cases; 13% of the dysplasia cases subsequently showed development of carcinoma. The age distribution revealed the prevalence of leukoplakia in the age-group 51-60 years; that of carcinoma in the age-group of 61-70 years. The sex distribution showed a male-female ratio of 3.2 : 1 in the leukoplakia-group, and a 1.9 : 1 ratio in the carcinoma-group. The tongue and the lips were the site of predilection for malignant transformation and for dysplasia. Among aetiological factors, Candida albicans infection and the simultaneous existence of several aetiological factors seemed to play a role in malignant transformation. Erosive leukoplakia showed the highest risk, developing in 25.9% of the cases into cancer.

Occurrence of epithelial dysplasia in oral leukoplakia. Analysis and follow-up study of 12 cases

The histologic material of 500 leukoplakia patients was analyzed in order to define the characteristics of epithelial dysplasia and to correlate the findings with the clinical data. Epithelial dysplasia was found in 120 cases (24 per cent) and was graded as mild, moderate, or severe. The occurrence of dysplasia was highest in the group of erosive leukoplakias. The majority of the severe dysplasias were found on the tongue and lips. Follow-up studies on sixty-eight leukoplakia patients with histologic dysplasia revealed carcinoma in nine cases (13.2 per cent) during the mean observation period of 6.3 years. Leukoplakias of the tongue showed the highest incidence of malignant change.

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.

Loss of epithelial blood group antigens A and B in oral premalignant lesions

Tissue from 40 oral premalignant lesions were investigated for the presence of blood group antigens A and B. The material included 18 leukoplakias, 1 erythroplakia, and 3 lichen planus, all with varying degrees of epithelial dysplasia, and 18 leukoplakias without histological evidence of impending malignancy. Thirty-eight benign keratotic oral muscosal lesions were included as a control group. The antigens were demonstrated by a double layer immunofluorescence technique, and the reactivity was compared, by titration, to the reactivity of adjacent normal epithelium from the same patient. All 22 lesions with dysplsia showed decreased reactivity for blood group antigen. Among the 18 leukoplakias without any signs of impending malignancy 4 cases demonstrated loss of antigen reactivity. None of 38 benign control lesions showed any change in antigen reactivity as compared to normal adjacent epithelium.