Fischler D F, Bauer T W, Tubbs R R
Department of Pathology, Cleveland Clinic Foundation, Ohio 44195-5138.
Histopathology. 1992 Dec;21(6):563-7. doi: 10.1111/j.1365-2559.1992.tb00445.x.
Monoclonal antibody anti-Leu19, is a marker of natural killer cells. Since reactivity between anti-Leu7, another natural killer cell marker, and small cell neuroendocrine carcinomas has been described, we evaluated the reactivity of anti-Leu19 in 92 neuroendocrine tumours. Frozen sections in each case were immunostained using the avidin-biotin-peroxidase complex method with monoclonal anti-Leu19. We found Leu19 expression in 93% of the cases. We also evaluated 149 other tumours, including adenocarcinomas, undifferentiated large cell carcinomas, lymphomas, melanomas and soft tissue tumours. We found Leu19 expression in 36% (by liberal interpretative criteria), or 29% (by conservative interpretative criteria) of these cases. Thus, while anti-Leu19 appears to be a sensitive marker for neuroendocrine tumours, a lack of specificity limits its practical application in diagnostic histopathology.