K. Schofield et al., THE CELL-ADHESION MOLECULE, E-CADHERIN, DISTINGUISHES MESOTHELIAL CELLS FROM CARCINOMA-CELLS IN FLUIDS, Cancer cytopathology, 81(5), 1997, pp. 293-298
BACKGROUND, The distinction between benign reactive mesothelial cells
and well differentiated carcinoma can be difficult in pleural, periton
eal, and especially pericardial fluids. E-cadherin is an adhesion prot
ein that is specifically expressed in cells of epithelial lineage. In
this study, anti-E-cadherin antibodies were used to identify and disti
nguish carcinoma cells from reactive mesothelial cells. METHODS. Pleur
al, peritoneal, and pericardial fluids were prepared using the Cytyc T
hin Prep((TM)) processor. The specimens were comprised of a mix of 45
cases that were diagnosed as carcinoma, suspicious, or reactive by Pap
anicolaou staining of routine material seen by the authors' service. R
outine immunologic techniques were used with a commercially available
E-cadherin antibody. RESULTS, In most cases of carcinoma, tumor cells
showed a strong positive membranous reaction product (32 of 37). This
included four cases that were not cytomorphologically diagnosed as mal
ignant, but subsequently proved to be malignant. E-cadherin staining w
as not observed in five tumors, two of which were not expected to expr
ess this protein. One benign case showed cells staining for E-cadherin
, although the cells were not malignant by morphologic criteria. Becau
se this case was a surgical pelvic washing, these cells more likely we
re epithelial contaminants than true false-positives. CONCLUSIONS, The
epithelial specific cell-cell adhesion marker E-cadherin reliably dis
tinguishes reactive mesothelial cells from carcinoma and is a useful a
djunctive test to distinguish benign reactive mesothelial cells from w
ell differentiated carcinoma cells in fluid specimens. (C) 1997 Americ
an Cancer Society.