The diagnostic value of thrombomodulin immunolocalization in serous effusions.
OBJECTIVE
To test the value of an antithrombomodulin monoclonal antibody as a diagnostic tool in detecting mesothelial cells and in differentiating mesothelioma from other malignant effusions.


METHODS
Thrombomodulin is a thrombin receptor that is distributed on surfaces where an anticoagulant activity is expected, including mesothelium. Antigen expression was studied by immunocytochemistry in 226 peritoneal and pleural exudates.


RESULTS
The antigen was found in 33 of 33 mesotheliomas, 35 of 35 reactive effusions, 57 of 145 carcinomatous fluids, and in one case of angiosarcoma among seven metastatic nonepithelial tumors. Three distinct staining patterns were demonstrated: (1) thin cell membranes in benign mesothelial cells; (2) thick cell membranes in mesotheliomas; and (3) cytoplasm in carcinomas. All squamous cell carcinomas had demonstrable thrombomodulin, suggesting that antigen expression likely correlates with squamous differentiation.


CONCLUSIONS
Thrombomodulin is of diagnostic utility in distinguishing mesothelioma from adenocarcinoma, provided the characteristic "thick membrane" pattern is present, but it should be used in panels with other markers of mesothelial and/or epithelial differentiation.
Ascoli
V
V
Dipartimento di Medicina Sperimentale e Patologia, Università La Sapienza, Rome, Italy.
Scalzo
C C
CC
Taccogna
S
S
Nardi
F
F
D000230:Adenocarcinoma / Q000737:chemistry / Q000175:diagnosis; D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor / Q000032:analysis*; D003937:Diagnosis, Differential; D004848:Epithelium / Q000276:immunology; D005122:Exudates and Transudates / Q000737:chemistry* / Q000166:cytology / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D008654:Mesothelioma / Q000737:chemistry / Q000175:diagnosis / Q000276:immunology; D009362:Neoplasm Metastasis / Q000276:immunology; D009369:Neoplasms / Q000175:diagnosis*; D018180:Thrombomodulin / Q000032:analysis*
D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D018180:Thrombomodulin