Identification of second malignancies on effusions and fine-needle aspirates using a panel of monoclonal antibodies.

The longer survival of neoplastic patients achieved through improvements of therapeutic regimens has increased the relative risk of developing a second primary tumour (SPT). In this context, conventional cytopathology can define tumour histotype only in a small fraction of cases. In this study, we have evaluated whether selected combinations of monoclonal antibodies (MAbs) to tumour-associated antigens (TAAs) can increase the accuracy of conventional morphology in detecting second primary tumours (SPTs) in two particularly difficult areas of cytodiagnosis, namely that of effusions and pulmonary fine-needle aspirates (FNAs). The immunocytochemical (ICC) analysis of 334 cytological specimens demonstrated that the use of our selected panel of MAbs could allow a more efficient identification of SPTs in comparison with conventional morphology. This diagnostic improvement was statistically significant (P < 0.0001). The present findings show that the immunophenotyping of effusions and FNAs, providing a more accurate and objective identification of SPTs, may have significant therapeutic and epidemiological relevance.