Diagnostic value of claudin-4 marker in pleural and peritoneal effusion cytology: Does it differentiate between metastatic adenocarcinoma and reactive mesothelial cells?


Department of Pathology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran


Background: Several markers have been used to make a distinction between metastatic adenocarcinoma and reactive mesothelial cells in the body cavity effusions. This study aimed to evaluate the diagnostic value of claudin-4 marker in making such a distinction.
Materials and Methods: In this cross-sectional study, a total of 92 pleural/peritoneol effusions have been studied, including 47 cases of definite metastatic carcinoma and 45 cases of reactive mesothelium, and definitely negative for malignancy. Specimens were collected from patients; cell block samples were derived and used for immunohistochemical staining. The antibody used for immunohistochemical labeling was monoclonal anti-claudin-4. In the evaluation, membrane-bound reactivity was considered as significant and positive cases were defined when at least more than 10% of tumor cells were distinctly labeled.
Results: Claudin-4 protein was positive in 40 specimens of metastatic carcinoma, while none of the cases of reactive mesothelium stained with the marker. This was not detected in the mesothelial cells, though. Positive staining for claudin-4 was significantly more frequent in metastatic carcinoma than in the reactive mesothelium (P > 0.0001). The sensitivity and specificity of claudin-4 to distinguish reactive mesothelium from metastatic carcinoma were 85% (95% confidence interval [CI], 71.1-93.8%) and 100% (95% CI, 91.1-100%), respectively. Furthermore, negative likelihood ratio was 0.15 (95% CI, 0.08-0.29).
Conclusion: The results of this study demonstrated that claudin-4 is less frequently expressed in reactive mesothelium. Thus, this claudin may be helpful in differentiating metastatic carcinoma from reactive mesothelial cells in pleural and peritoneal fluid cytology specimen.


1. Ensani F, Nematizadeh F, Irvanlou G. Accuracy of immunohistochemistry in evaluation of malignant pleural and peritoneal effusions. Pol J Pathol 2011;62:95-100.  Back to cited text no. 1
2. Thapar M, Mishra RK, Sharma A, Goyal V, Goyal V. Critical analysis of cell block versus smear examination in effusions. J Cytol 2009;26:60-4.  Back to cited text no. 2
[PUBMED]  Medknow Journal  
3. Magyarosy E, Martin WJ, Chu EW, Martin SE. Differential diagnostic significance of the paucity of HLA-I antigens on metastatic breast carcinoma cells in effusions. Pathol Oncol Res 1999;5:32-5.  Back to cited text no. 3
4. Corson JM, Pinkus GS. Mesothelioma: Profile of keratin proteins and carcinoembryonic antigen: An immunoperoxidase study of 20 cases and comparison with pulmonary adenocarcinomas. Am J Pathol 1982;108:80-8.  Back to cited text no. 4
5. Said JW, Nash G, Banks-Schlegel S, Sassoon AF, Murakami S, Shintaku IP. Keratin in human lung tumors. Patterns of localization of different-molecular-weight keratin proteins. Am J Pathol 1983;113:27-32.  Back to cited text no. 5
6. To A, Coleman DV, Dearnaley DP, Ormerod MG, Steele K, Neville AM. Use of antisera to epithelial membrane antigen for the cytodiagnosis of malignancy in serous effusions. J Clin Pathol 1981; 34:1326-32.  Back to cited text no. 6
7. Morin PJ. Claudin proteins in human cancer: Promising new targets for diagnosis and therapy. Cancer Res 2005;65:9603-6.  Back to cited text no. 7
8. Tsukita S, Furuse M, Itoh M. Multifunctional strands in tight junctions. Nat Rev Mol Cell Biol 2001;2:285-93.  Back to cited text no. 8
9. Rahner C, Mitic LL, Anderson JM. Heterogeneity in expression and subcellular localization of claudins 2, 3, 4, and 5 in the rat liver, pancreas, and gut. Gastroenterology 2001;120:411-22.  Back to cited text no. 9
10. Sasaki H, Matsui C, Furuse K, Mimori-Kiyosue Y, Furuse M, Tsukita S. Dynamic behavior of paired claudin strands within apposing plasma membranes. Proc Natl Acad Sci U S A 2003;100:3971-6.  Back to cited text no. 10
11. Le Moellic C, Boulkroun S, González-Nunez D, Dublineau I, Cluzeaud F, Fay M, et al. Aldosterone and tight junctions: Modulation of claudin-4 phosphorylation in renal collecting duct cells. Am J Physiol Cell Physiol 2005;289:C1513-21.  Back to cited text no. 11
12. Katahira J, Inoue N, Horiguchi Y, Matsuda M, Sugimoto N. Molecular cloning and functional characterization of the receptor for Clostridium perfringens enterotoxin. J Cell Biol 1997;136:1239-47.  Back to cited text no. 12
13. Soini Y. Expression of claudins 1, 2, 3, 4, 5 and 7 in various types of tumours. Histopathology 2005;46:551-60.  Back to cited text no. 13
14. Gress TM, Müller-Pillasch F, Geng M, Zimmerhackl F, Zehetner G, Friess H, et al. A pancreatic cancer-specific expression profile. Oncogene 1996;13:1819-30.  Back to cited text no. 14
15. Geng MM, Ellenrieder V, Wallrapp C, Müller-Pillasch F, Sommer G, Adler G, et al. Use of representational difference analysis to study the effect of TGFB on the expression profile of a pancreatic cancer cell line. Genes Chromosomes Cancer 1999;26:70-9.  Back to cited text no. 15
16. Murugan P, Siddaraju N, Habeebullah S, Basu D. Immunohistochemical distinction between mesothelial and adenocarcinoma cells in serous effusions: A combination panel-based approach with a brief review of the literature. Indian J Pathol Microbiol 2009;52: 175-81.  Back to cited text no. 16
[PUBMED]  Medknow Journal  
17. Shi SR, Shi Y, Taylor CR. Antigen retrieval immunohistochemistry: Review and future prospects in research and diagnosis over two decades. J Histochem Cytochem 2011;59:13-32.  Back to cited text no. 17
18. Ordóñez NG. What are the current best immunohistochemical markers for the diagnosis of epithelioid mesothelioma? A review and update. Hum Pathol 2007;38:1-16.  Back to cited text no. 18
19. Soini Y, Kinnula V, Kahlos K, Pääkkö P. Claudins in differential diagnosis between mesothelioma and metastatic adenocarcinoma of the pleura. J Clin Pathol 2006;59:250-4.  Back to cited text no. 19
20. Kleinberg L, Holth A, Trope CG, Reich R, Davidson B. Claudin upregulation in ovarian carcinoma effusions is associated with poor survival. Hum Pathol 2008;39:747-57.  Back to cited text no. 20
21. Davidson B, Zhang Z, Kleinberg L, Li M, Flørenes VA, Wang TL, et al. Gene expression signatures differentiate ovarian/peritoneal serous carcinoma from diffuse malignant peritoneal mesothelioma. Clin Cancer Res 2006;12:5944-50.  Back to cited text no. 21
22. Hough CD, Sherman-Baust CA, Pizer ES, Montz FJ, Im DD, Rosenshein NB, et al. Large-scale serial analysis of gene expression reveals genes differentially expressed in ovarian cancer. Cancer Res 2000;60:6281-7.  Back to cited text no. 22
23. Lódi C, Szabó E, Holczbauer A, Batmunkh E, Szíjártó A, Kupcsulik P, et al. Claudin-4 differentiates biliary tract cancers from hepatocellular carcinomas. Mod Pathol 2006;19:460-9.  Back to cited text no. 23
24. Lonardi S, Manera C, Marucci R, Santoro A, Lorenzi L, Facchetti F. Usefulness of Claudin 4 in the cytological diagnosis of serosal effusions. Diagn Cytopathol 2011;39:313-7.  Back to cited text no. 24
25. Facchetti F, Lonardi S, Gentili F, Bercich L, Falchetti M, Tardanico R, et al. Claudin 4 identifies a wide spectrum of epithelial neoplasms and represents a very useful marker for carcinoma versus mesothelioma diagnosis in pleural and peritoneal biopsies and effusions. Virchows Arch 2007;451:669-80.  Back to cited text no. 25