Demonstration of keratin in human adenocarcinomas.

The occurrence and localization of intermediate-sized filaments in 85 cases of adenocarcinoma have been examined by the indirect immunofluorescence technique as well as by the immunoperoxidase technique. Frozen sections of human tumor tissue were incubated with antibodies to keratin, vimentin, and desmin. In contrast to earlier studies by Schlegel et al, this study demonstrates the presence of keratin in 64 cases of primary adenocarcinoma, including tumors of stomach, colon and rectum, lung, pancreas, bile ducts, ovary and uterus, female breast, and prostate, and in 21 cases of adenocarcinomatous metastases in lymph nodes, thoracic and abdominal wall, omentum, mesentery, testis, liver, and the pelvis. In order to establish the possibility of demonstrating intermediate filament proteins by immunohistochemical techniques in fixed, paraffin-embedded material, the authors tested seven fixation methods. It is concluded from the data that antibodies to intermediate filament proteins can be useful in the differential diagnosis of adenocarcinomas because they can distinguish them from tumors of nonepithelial origin in frozen sections.