Md. Lozano et al., Immunocytochemistry in the differential diagnosis of serous effusions - A comparative evaluation of eight monoclonal antibodies in Papanicolaou stained smears, CANC CYTOP, 93(1), 2001, pp. 68-72
BACKGROUND. The distinction between pleural mesothelioma (MS), reactive mes
othelium (RM), and adenocarcinoma (AC) in serous effusions continues as a d
iagnostic problem in pathology. Immunohistochemistry can help, especially i
n surgical samples, but the optimum panel of antibodies has yet to be repor
ted. The application of these antibodies to serous effusions has displayed
variable results. The aim of this study Was to evaluate the usefulness of e
ight monoclonal antibodies in the differential diagnosis of MS, RM, and AC
in serous effusions.
METHODS. A total of 44 cytologic specimens of serous effusions (26 pleural,
15 peritoneal, and 3 pericardial) from 30 ACs, 3 MSs, and 11 RMs, previous
ly stained with Papanicolaou stain, were selected retrospectively from our
files and stained with HBME-1, thrombomodulin, calretinin, MOC-31, Ber-EP4
E-cadherin, CEA, and CD-15. The immunoreactions were evaluated independentl
y by two pathologists. A stepwise logistic regression analysis was applied
to the data to select an appropriate panel of antibodies.
RESULTS. Statistical significance was found with HBME-1, thrombomodulin, MO
C-31, Ber-EP4, and CD-15, when comparing both AC versus MS, and PLC versus
any type of mesothelial proliferation CMS or RM). Using HBME-1, 80% of ACs
were negative whereas all three MSs reacted strongly with P = 0.003. A P =
0.02 was reached with thrombomodulin with 76.5% of ACs showing no immunorea
ctivity. Ber-EP4 and MOC-31 displayed good results with a P < 0.001 and 0.0
1, respectively. CD-15 reached a P = 0.034. No differences were found using
the other antibodies. Ten ACs, all 3 MSs, and 10 RMs were double immunosta
ined with HBME-1 and/or MOC-31 and Ber-EP4 successfully.
CONCLUSIONS. Immunohistochemical studies performed on Papanicolaou stained
cytologic smears proved to be useful in the differentiation between metasta
tic AC and mesothelial proliferation. HBME-1, thrombomodulin, MOC-31, Ber-E
P4, and CD-15 were the most useful. In selected cases, it appeared that dou
ble immunostaining aided the differential diagnosis. Cancer (Cancer Cytopat
hol) 2001;93:68-72, (C) 2001 American Cancer Society.