MARKERS FOR METASTATIC ADENOCARCINOMA IN SEROUS EFFUSION SPECIMENS

A variety of stains have been proposed as useful adjuncts to the morph ologic diagnosis of serous effusion specimens. This study evaluates th e sensitivity and specificity of nine stains for the detection of meta static adenocarcinoma in effusions. Mucin cytochemistry with the Perio dic acid-Schiff reaction after diastase digestion (PASd) and the mucic armine method, as well as immunochemical staining for five glycoprotei n antigens, was undertaken on 153 effusion specimens with histological and/or clinically confirmed diagnoses. Immunochemical stains included three antibodies to CEA (Dako polyclonal, 4E7 and A5B7) and antibodie s to HEA (Ber-EP4), TAG 72 (B72.3), CD15 (LeuM1) and Epithelial membra ne antigen (EMA) were evaluated. The sensitivity of the stains for ade nocarcinoma (102 cases) was: PASd 37%; mucicarmine 24%; polyclonal ant i-CEA 69%, 4E7 52%; A5B7 21%; EMA 91%; B72.3 44%; Ber-EP4 32%, LeuM1 2 4%. With the exception of EMA, none of the stains reacted with any cas es of benign mesothelial cells (II cases), reactive mesothelial cells (34 cases), or with six cases of mesothelioma. However, EMA staining w as present in two cases (6%) of reactive mesothelial cells and all cas es of mesothelioma. The optimal combination of stains for use in a pan el was polyclonal anti-CEA/B72.3/PASd. Combined results from these thr ee stains yielded a sensitivity of 83% for adenocarcinoma with no fals e positive results. It is concluded that special staining may provide valuable information to assist in the classification of difficult effu sion cases. (C) 1994 Wiley-Liss, Inc.