Tumor oncogenic expression in malignant effusions as a possible method to enhance cytologic diagnostic sensitivity. An immunocytochemical study of 87 cases.

The diagnostic ability of cytological preparations can be hampered by specimen inadequacy and the presence of representative cells, which may result in a diagnostic accuracy of only 70%. An immunocytochemical battery (ICC), which included anti-p53, anti-c-erbB-2, and B72.3 MoAbs, was used to enhance sensitivity in 87 specimens of body effusions. Thirty-six cases were positive for malignancy using conventional cytology. Forty cases were negative and 11 cases were inconclusive or had an equivocal diagnosis. Sensitivity was 65%, and there was a negative predictive value (NPV) of 62%. p53 was expressed in 50 cases (56%, sensitivity = 83%, NPV = 73%), and B72.3 MoAb was positive in 36 cases (37%, sensitivity = 66%, NPV = 64%). Forty-eight cases (56%) displayed reactivity with anti-c-erbB-2 (sensitivity = 75%, NPV = 63%). The authors concluded that application of an ICC panel of anti-p53, B72.3 and c-erbB-2 to complement conventional cytology increases sensitivity to 98% (P < .0005) with an NPV of 96% (P = .001).