The use of a panel of monoclonal antibodies can lower false-negative diagnoses of peritoneal washings in ovarian tumors.

A correct surgical staging of ovarian carcinoma and the identification of persistent microscopic disease at second-look surgery largely rely on the cytologic examination of peritoneal washings (PW). Nevertheless, the morphologic analysis of these fluids frequently provides false-negative findings. As shown in other areas of cytodiagnosis, monoclonal antibodies (MoAb) to tumor-associated antigens may be a useful adjunct to overcome the limitations of conventional cytopathologic examination of PW. To evaluate this question, immunocytochemical tests were done using a panel of four MoAb to ovarian carcinoma-associated antigens (B72.3, MOv18, MOv19, and OC-125) to analyze 117 PW sampled during initial surgical staging and 121 PW harvested at second-look operations. The results of this study showed that immunocytochemical tests using the combination of the four reagents could improve cytodiagnosis more than 15% in both groups of PW. Thus a significant fraction of patients could be correctly staged and treated or become potentially curable by second-line salvage therapy.