Immunophenotyping of Mesothelial Cells and Carcinoma Cells With Monoclonal Antibodies to Cytokeratins, Vimentin, Cea and Ema Improves the Cytodiagnosis of Serous Effusions

This paper presents an immunocytochemical study performed on cytocentrifuged deposits from 109 peritoneal and pleural effusions including 20 transudates, 43 malignant metastatic effusions and 46 effusions containing atypical cells, unidentifiable as reactive mesothelial or malignant epithelial cells on the classical morphological criteria. A panel of four monoclonal antibodies (MAb) was used, including KL1 directed to cytokeratins (KER), V9 to vimentin (VIM), NEO 723 to carcinoembryonic antigen (CEA) and E29 to epithelial membrane antigen (EMA). In most transudates the reactive mesothelial cells coexpressed VIM and KER with a ring-like pattern for the latter proteins. In contrast, they were unreactive to anti-CEA and weakly and inconsistently reactive to anti-EMA. In malignant effusions, most carcinoma cells coexpressed EMA, CEA and KER with a predominant diffuse cytoplasmic pattern for the latter. Only a few malignant epithelial cells from five metastatic adenocarcinomas weakly expressed VIM. When used on the 46 effusions with unidentifiable cells, the panel of MAb allowed reactive mesothelial cells and malignant epithelial cells to be distinguished from each other in 39 of 46 cases (85%).     

Identification of Malignant Cells In Serous Effusions Using A Panel of Monoclonal Antibodies Ber-Ep4, Mca-B-12 and Ema

A panel of three monoclonal antibodies (MoAbs) was tested on 29 benign and 53 malignant effusions with the aim of investigating its usefulness for the discrimination between benign and malignant lesions. The panel consisted of MoAbs directed against epithelial membrane antigen (EMA); MCA-b-12, reacting with a 350 kD glycoprotein with mucin-like characteristics present on human breast cancer cells and various other normal and neoplastic tissues, and Ber-EP4, directed against a 34 and 39 kD glycopeptide on human epithelial cells but not on mesothelium. Fifty-two (98%) of the malignant effusions reacted with EMA, 49 (92%) with MCA-b-12 and 44 (83%) with Ber-EP4. Fourteen per cent of benign effusions reacted with EMA, 17% with MCA-b-12 and 7% with Ber-EP4. All seven effusions obtained from patients with a malignant mesothelioma reacted with EMA, six of the seven cases staining intensively. None of the seven stained with Ber-EP4. MCA-b-12 did not react with the cells in one case of malignant mesothelioma. The results suggest that the combination of EMA and Ber-EP4 may be used to discriminate between benign and malignant cells and possibly also between adenocarcinoma and malignant mesothelioma. MCA-b-12 followed in general the reaction pattern of EMA, although often with a less intense staining reaction, making this antibody unsuitable for inclusion in the panel.     

Immunocytochemical Staining of Serous Effusions: an Additional Method In the Routine Cytology Practice?

In a consecutive and prospective cytomorphologic and immunocytochemical study we have examined 100 serous fluids with a panel of antibodies. Three different immunocytochemical patterns of staining were recognized: (i) a benign profile showing no Ber-EP4 or CEA-positive cells; (ii) a malignant profile with Ber-EP4 and strongly EMA-positive epithelial cells; and (iii) a malignant profile in which mesothelial cells were strongly positive for EMA. By applying these profiles the number of malignant cases recognized increased from 19 to 38. All cytomorphologic malignant fluids showed a malignant profile, but in two cases a malignant epithelial profile was found in patients without otherwise proven malignant disease (false positive staining). Immunocytochemistry with anti-Ber-EP4 and anti-EMA can be recommended as a routine procedure, but the marker result should always be correlated with cytomorphology, eventual histologic data and clinical records. Dans cette étude cytomorphologique prospective, nous avons analysé 100 liquides d'épanchement des séreuses, consécutifs, à l'aide d'une batterie d'anticorps. Trois profils immunocytochimiques différents ont été individualisés: (i) un profil bénin dans lequel aucune cellule n'est positive avec Ber-EP4 ou l'ACE, (ii) un profil malin avec des cellules épithéliales fortement positives aves Ber-EP4 et avec l'EMA et (iii) un profil malin dans lequel les cellules mésothéliales sont fortement positives avec l'EMA. En appliquant ces notions de profils, le nombre de cas malins reconnus passe de 19 à 38. Tous les cas cytologiquement malins avaient un profil malin, mais 2 cas de profil immunocytochimique épithélial malin correspondaient à des patients chez lesquels aucune pathologie maligne n'a été trouvée (faux positif). L'immunocytochimie avec l'anti Ber-EP4 et l'anti EMA doit être recommandée en pratique de routine, mais les résultats de ces immunomarquages doivent toujours être corrélés avec l'étude morphologique et les éventuelles données histologiques et cliniques. In einer prospektiven cytomorphologischen und immuncytochemischen Studie wurden 100 seröse Ergüsse mit einer Gruppe von Antikörpern überprüft. Es fanden sich 3 unterschiedliche Reaktionsmuster: (i) eine gutartige Gruppe ohne positive Reaktion auf Ber-EP4 oder CEA, (ii) eine maligne Gruppe mit Ber-EP4 positiven und stark positiven EMA-Zellen und (iii) eine maligne Gruppe mit stark positiven mesothelialen Zellen auf EMA. Unter Anwendung dieser Einteilung konnte die Zahl der diagnostizierten malignen Fälle von 19 auf 38 vergrößert werden. Alle cytologisch malignen Fälle entsprachen den malignen Gruppen, während 2 Patienten mit immuncytochemisch positiven Befund keinerlei Malignitätszeichen aufwiesen. Der immuncytochemische Einsatz von Anti Ber-EP4 und Anti EMA kann als Routineverfahren empfohlen werden, wobei jedoch immer eine Korrelation mit der Cytomorphologie oder histologischen und klinischen Daten berücksichtigt werden sollte.