“…The expanding use of immunocytochemical methods may indeed result in a fulfillment of the above mentioned expectations (34). This would be obtained by the performance of multicenter validation (35) studies of immunocytodiagnostic protocols, which would in part be facilitated by the use of MoAbs of more restricted tumor specificity that may become available. In contrast to conventional cytopathology, the use of immune reagents is likely also to introduce "internal" and "external" quality control assessment criteria in an area of diagnosis which is hardly ever subjected to this standard control (36,37).…”