Scanning electron microscopy of different types of oral leukoplakia: comparison with normal and malignant oral mucosa.

The present study analysed surface architecture of normal, premalignant and malignant oral mucosa using scanning electron microscopy to evaluate its role in early diagnosis of potentially malignant oral lesions. The surface ultrastructure of the buccal mucosa in tobacco chewers showed variations from that of non-chewers. Homogenous leukoplakia demonstrated well-defined intercellular junctions and the microrugal surface pattern as seen in normal mucosa. In verrucous leukoplakia, the surface layer consisted of characteristically-shrunken desquamated hyperkeratotic cells. Erosive leukoplakia had a discontinuous superficial layer along with complete loss of intercellular ridges. Speckled leukoplakia also showed marked abnormalities such as thickened irregular protrusions and evidence of a villus-like pattern. These villus-like structures were comparatively prominent in leukoplakia showing dysplasia. Oral carcinoma showed marked altered surface ultrastructure and had a pattern similar to dysplastic lesions. The irregular swollen elongated protrusions with villous-like structures that were observed in carcinoma and dysplastic lesions can, therefore, be considered as surface markers for potentially malignant leukoplakia.

[Two cases of oral leukoplakia possibly associated with human papillomavirus].

Two cases of oral leukoplakia were studied immunohistologically and ultrastructurally. By means of avidin-biotin peroxidase complex technique using papillomavirus specific antibody, distinct nuclear staining of epithelial cells of middle and upper layers was observed in both cases. Further evidence for the presence of human papillomavirus was obtained by the electron micrograph, which revealed virus-like particles (30-40 nm in diameter) within the nucleus.

[Leukoplakia of the bladder]. / Leikoplakiia mochevogo puzyria.

The urinary bladder leukoplakia from 42 patients was studied clinico-morphologically, histochemically and electron microscopically. This precancerous condition is observed in 58,3 cases of chronic cystitis, more frequently in females. Three successive stages of the leukoplakia development under the conditions of the inflammatory process can be distinguished: squamous-cell modulation, squamous-cell metaplasia, squamous-cell metaplasia with keratinization. The formation of fissure-like intercellular bridges and the appearance of the long dense bundles of tonofibrils in the cytoplasm are the early ultrastructural signs of squamous-cell metaplasia of the transitional epithelium which are of the differential-diagnostic importance.

Leukoplakia of the prepuce with epidermolytic hyperkeratosis: a case report.

A leukoplakic lesion of the prepuce is described with the histologic and ultrastructural features of epidermolytic hyperkeratosis. The lesion represents most likely a variant of epidermolytic leukoplakia recently observed in the vermilion border of the lip.

[Role of endoscopic studies and cytogenetic indices in diagnosis of preclinical variants of cervix neoplasms]. / Znachenie éndoskopicheskikh issledovanii i tsitogeneticheskikh pokazatelei v raspoznavanii preklinicheskikh form raka sheiki matki.

The results of colpocervicoscopic examination of more than 15,000 females suggested cervical carcinoma in 345 cases, which was confirmed histologically in 319 patients. A detailed morphological and cytogenetic investigation carried out in 36 patients with preclinical form of TIaNXMO invasive carcinoma of cervix uteri established a relationship of mitotic activity, pathological mitosis count and fraction of cells with X-chromatin, on the one hand, and the depth of tumor invasion, on the other. The stages of complex examination of patients with pathology of cervix uteri are discussed.

An ultrastructural study of epidermolytic leukoplakia.

A leukoplakic lesion of the lip showing the histologic features of epidermolytic hyperkeratosis above solar elastosis was investigated by electron microscopy. The ultrastructural alterations observed in the upper epidermal layers corresponded in the main with those of epidermolytic hyperkeratosis in other skin diseases. The keratinocytes showed irregularly formed tonofilaments, a marked intracellular edema, and premature cornification. In addition, there were discrete subcellular signs of premalignancy in the cells of the basal and suprabasal layers. These alterations suggest that the epidermolytic leukoplakia represents a rare histopathologic variant of actinic cheilitis.

[Chronic cystitis in the aspect of its relationship with precancerous conditions]. / Khronicheskie tsistity v aspekte ikh prinadlezhnosti k predraku.

A morphological analysis of biopsy specimens from 32 patients with chronic cystitis allowed proliferative and nonproliferative forms of the disease to be distinguished. Chronic cystitis with von Brunn cell nests, cystic and glandular cystitis comprise different stages of the same pathological process which shows no trend for malignization. They may be considered to be the background diseases in the development of the bladder cancer. Vesical leukoplakia tends to malignancy and should be considered as a facultative precancer. Structural-metabolic reorganization in the connective tissue of the submucous layer with impairment of the vessel wall permeability regularly precedes the development of proliferative changes in the epithelial layer of the bladder wall.

Early changes of dog esophageal mucosa induced by N-ethyl-N'-nitro-N-nitrosoguanidine.

Early changes in the esophageal mucosa of dogs induced by N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) were studied. Seven one-year-old beagle dogs were given a solution of 250 micrograms ENNG/ml to drink ad libitum for 4 months. Three different kinds of lesions (10 erosive carcinomas, 4 slightly elevated microcarcinomas and 19 leukoplakias) were recognized. These three kinds of lesions were not located adjacent to one another, and were surrounded by almost normal stratified squamous epithelium. The foci of the carcinomas revealed an abrupt transition to normal epithelium and were considered to have arisen abruptly from normal esophageal epithelium. The histogenesis of squamous cell carcinomas of the esophagus in dogs may differ from that in man.

[Disorder of the microfolds and tonofibrils in cervical leukoplakia]. / Narushenie sostoianiia mikroskladok i tonofibrill pri leikoplakii sheiki matki.

The ultrastructure of superficial cells of the normal human cervical squamous epithelium and that in leukoplakia was examined by scanning and transmission electron microscopy. The characteristic appearance of normal cells is described. Changes in the concentration of tonofilaments and formation of keratohyalin granules were revealed in leukoplakia. Alterations in surface microridges were also observed. The latter phenomenon is closely related to a decrease in the number of tonofilaments at the cell periphery. It is possible that the altered microridges do not retain the cushioning protective mucin and maintain the stationary of progressive states of leukoplakia.