Studies on the histopathological and histochemical changes in oral lichen planus and the apparently healthy nearby areas

Biopsy specimens from 20 patients affected with lichen planus [L.P] were taken from diseased oral mucosa [gingival, lip or cheek] and nearby areas. Control biopsies were taken from similar situation from 3 healthy volumteer persons. All biopsies were studied histologically using HX and E and Mallory stains and histochemically using PAS, methyl green pyronin, toluldine blue and mercury-bromophenol blue stains. Histologically it was found that parakeratosis, acanhosis, irregular downward txtension of the epithelium and hydrpic degeneration in stratum basale and stratum spinosum were prominent in the epidermis of the diseased areas. The nearby areas, showed similar epidermal affection but to a lesser degree. In the lesion areas, the underneath connective tissue [C.T.] showed wide band of cellular infiltration with dilated blood capillaries. These changes were not evident in the nearby areas but fibrosis was evident. Istochemically, the basement membrane [B.M.] was thick and irregular with rare interruptions in both diseased and nearly areas. The DNA decreased in germinal layer and increased in parakeratolic and inflammatory cells compared to the controls. The RNA was high in stratum spinosum of the diseased area only. Mast cells increased obviously in the underneath C.T. of the diseased area and to a lesser degree in the nearby area. Protein contents was decreased in hydropic cells only, but increased in parakeratotic areas. It was concluded that in L.P. the actual lesion incidence both the visible disease and the apparently normal looking nearby areas

Correlation between histological and radiographical appearance of periapical radiolucencies

One hundred and eighteen patients complaining of periapical lesions were examined clinically and radiographically. All lesions were surgically enucleated and examined histopathologically. From this study, it was concluded that the clinical-radiographical readings were recorded as follows: 5.9%, 26.3% and 67.8% for cystic, abscesses and granulomatous lesions, respectively. The histopathological findings for the whole cases were also recorded. 16.1% were cystic lesions, 21.2% were abscesses and 60.2% were granulomas and 2.5% were other things rather than abscess, cyst or granuloma. The difference was statistically significant between the clinical-radiographic readings by the three observers and histopathological findings as regard to the percentages of cystic lesions, while the clinical- radiographic readings as regard to the percentages of abscesses and granulomas lesions were statistically not significant when compared with the histopathological findings. Due to the large variations between the findings and readings of the different observers, the clinical-radiographic evaluations only of the periradicular lesions could not be relied on to achieve an accurate diagnosis. Histopathological study is the only accurate way to differentiate between any periapical radiolucent lesions and to reach to the correct diagnosis specially periapical granuloma and chorionic periapical abscess

Immunohistochemical study of epithelial membrane antigen in araplastic, metastatic carcinomas and malignant lymphomas

20 cases of primary metastatic tumours of epithelial origin and non Hodgkin's lymphomas were studied by the immunoperoxidase method to determine the reaction and the distribution of epithelium membrane antigen [EMA] with the use of monoclonal antibody. Well and moderately differentiated epithelial tumours, as well as adenocystic carcinoma reacted positively with EMA, whereas anaplastic carcinomas and lympho-epithelioma demonstrated low positivity of EMA. In metastatic tumours, micrometastasis of epithelial origin expressed EMA positively, while the lymphoid tissues around them were negative. Non Hodgkin's lymphomas also reacted negatively with EMA