Use of antibodies or binding portions thereof, probes, ligands, or other biological agents which either recognize an extracellular domain of prostate specific membrane antigen (PSMA) or bind to and are internalized with PSMA. These biological agents can be labeled and used for detection of cancerous tissues, particularly cancerous tissues proximate to or containing vascular endothelial cells, which express an extracellular domain of PSMA. The labeled biological agents can also be used to detect normal, benign hyperplastic, and cancerous prostate epithelial cells or portions thereof. They also can be used alone or bound to a substance effective to ablate or kill such cells as a therapy for prostate or other cancers. Also disclosed are four hybridoma cells lines, each of which produces a monoclonal antibody recognizing extracellular domains of PSMA of normal, benign hyperplastic, and cancerous prostate epithelial cells or portions thereof.