The monoclonal antibody 7E12H12 can differentiate primary adenocarcinoma of the bladder and prostate

Objective To determine if the monoclonal antibody 7E12H12, which reacts with a 40 kDa protein in normal human enterocytes and has been shown to be a marker for intestinal metaplasia and adenocarcinoma arising in the bladder, could assist in distinguishing prostatic, urachal and vesical adenocarcinoma, using a sensitive immunohistochemical assay. Materials and methods Fifteen primary prostatic adenocarcinomas and five adenocarcinomas of the urinary bladder were selected for a retrospective evaluation. The monoclonal antibody 7E12H12 (IgM isotype) was used in an immunoperoxidase assay to survey formalin-fixed, paraffin-embedded archival tissue specimens. Results All vesical adenocarcinomas reacted positively with the antibody, regardless of grade; none of the 15 prostatic specimens reacted positively in either the benign or malignant glandular epithelium. Conclusion The monoclonal antibody 7E12H12 can differentiate primary adenocarcinoma of the bladder from secondary adenocarcinoma arising in the prostate and may be a useful tool in diagnostic pathology.