[Immunohistological coexpression of keratin and vimentin in the epithelial neoplastic cells].

Filed formalin-fixed paraffin blocks of 128 cases of epithelial neoplasms were selected for immunohistochemical study of keratin and vimentin expression. The results showed that 35.1% (45/128) of different carcinomas expressed vimentin. The immuno-positivity of vimentin in thyroid carcinomas, ovarian carcinomas, prostatic adenocarcinomas, pulmonary carcinomas and malignant mesotheliomas were 81.8%, 42.8%, 66.7%, 30.5% and 53.4%, respectively. Carcinomas of breast, kidneys, salivary glands, adrenal glands and nasopharyngeal carcinomas also showed various degrees of positive reaction. The results suggest that an immunohistochemical positive vimentin reaction does not exclude histopathological diagnosis of carcinomas. The significance and noticeable aspects of immunohistochemical methods in histopathological diagnosis are also discussed.

Immunoreactive beta-endorphin in ovarian sex cord-stromal tumors.

The possible production of the opioid polypeptide beta-endorphin (beta-EP) was investigated in paraffin-embedded tissue from 17 ovarian tumors with the use of a specific anti-beta-EP antibody and the avidin-biotin-peroxidase staining technique. Only sex cord-stromal tumors (ten cases) showed positive staining. Strong beta-EP immunoreactivity was present in Leydig's cells of Sertoli-Leydig cell tumors; weaker sporadic staining was present in cells of granulosa cell tumors, and faint staining was present in occasional, luteinized theca cells of fibrothecomata. These findings suggest that cells with the sex cord-stromal phenotype that are capable of steroid production can also produce beta-EP. The latter may be a component of the "functional" status associated with some ovarian sex cord-stromal tumors and may serve as a helpful marker in distinguishing this type of tumors from germ cell or epithelial neoplasms.

Secretory component: a glandular epithelial cell marker.

Secretory component (SC) has been demonstrated to be produced by both normal and malignantly transformed glandular epithelial cells. By an indirect immunofluorescent technique, this study surveys tumors of varied cellular origin in order to determine the reliability of SC as a marker for tumor cells derived from glandular epithelium. Both primary and metastatic tumors of glandular epithelial origin demonstrated SC fluorescence, while nonglandular epithelial tumors did not. This observation was extended to live single-cell preparations, which demonstrated intense cell-surface fluorescence only when glandular epithelial tumors cells were examined. Additionally, fixed, cytocentrifuged, single-cell preparations of glandular epithelial tumors demonstrated cytoplasmic SC fluorescence. When breast carcinoma was examined, all cases demonstrated SC, regardless of the degree of differentiation. This assay appears to have useful clinical application in that the finding of SC provides indication of the glandular epithelial origin of a malignantly transformed cell.