IMMUNOCYTOCHEMICAL DIFFERENTIATION OF REACTIVE MESOTHELIAL CELLS AND ADENOCARCINOMA CELLS IN SEROUS EFFUSIONS WITH THE USE OF CARCINOEMBRYONIC ANTIGEN AND FIBRONECTIN

Ninety effusions from patients with breast and ovarian cancer were stu died cytologically and classified as benign, suspicious or malignant, and the same samples were studied for carcinoembryonic antigen (CEA) a nd fibronectin (F) immunostaining. The combination F positive/CEA nega tive was found to have 100% specificity and 92.3% sensitivity in patie nts with benign or reactive effusions, and F negative/CEA positive 85. 7% specificity and 80.7% sensitivity for malignancy. Immunostaining pr ovides valuable supplementary information in cytologically suspicious patients. int the presence of F negative/CEA negative effusions, it is probable that insufficient cellular material is present for either a cytologic or immunostaining diagnosis.