Immunohistochemical localization of S-100 protein in benign and malignant lesions of the breast

Immunohistochemical identification of S-100 protein using monoclonal antibody with peroxidase antiperoxidase technique was performed on 40 specimens of benign and malignant breast lesions. S-100 was expressed in 19 cases [47.5%] with a higher incidence in medullary carcinoma [87.5%]. S-100 immunoreactivity was considered as a marker for myoepithelial cells and used to distinguish between benign and malignant lesions. The discrepancy of staining results with antibody to S-100 protein can be explained by methods of fixation and immunohistochemical techniques used

Gastric metaplasia of duodenal mucosa and Helicobacter pylori organism in duodenal ulcer patients

Endoscopic biopsies from gastric antrum and duodental bulb were taken from 30 chronic active doudenal ulcer patients to evaluate the association between gastric metaplasia and degree of duodenal and antral inflammation and the presence of H. pylori organism in gastric and duodenal biopsies. Duodenal and antral gastritis was present in all cases [100%]. Gastric metaplasia was found in 80% of duodenal biopsies. H. pyllori organism was found in 90%, 80% of antral and duodenal biopsies, respectively. This study indicated that H. pylori organism and gastric metaplasia can be a factor in pathogenesis of duodenitis and duodenal ulceration

Immuno histochemical study of epithelial and lymphocytic components of adenolymphoma

Eighteen cases of adenolymphoma were investigated using 3 immunhistochemical stains to clarify the histogenesis of adenolymphoma: Positive immunoreactive cells could be detected in the epithelial component of the tumour using cytokeratin anti-body, thus supporting the concept of its ductal origin. S-100 protein positive cells in-between the epithelial cells and in between the lymphoid stroma could detected using S-100 protein antibody. The morphologic appearance of these cells was identical to that of Langerhan's cells indicating that delayed hypersensitivity may be a pathogenic factor in the development of adenolymphoma. Also, using monoclonal antibody against T-cell fraction, the T-helper cells was more predominant than T-suppressor indicating that the lymphoid stroma was an activated one within the physiological range of normal lymph node. Mast cells were detected in-between the epithelium and in subepithelial stroma by toluidine blue reaction, which may have a direct proliferative effect on the epithelium