Differentiation of peritoneal mesothelioma and serous carcinoma of the ovary / peritoneum

Ovarian serous carcinomas are about ten times as common as primary peritoneal carcinomas17.

The differentiation of peritoneal epithelioid mesothelioma from serous papillary carcinoma of the ovary or peritoneum can be problematic. Most studies of the immunohistochemical differentiation of mesothelioma from adenocarcinoma have concentrated on pleural mesotheliomas and in particular the differentiation from pulmonary adenocarcinomas. However, several of the markers that are of proven utility in this context are less informative in the differentiation from ovarian/peritoneal serous carcinoma. WT1 and mesothelin are positive in both mesothelioma and serous carcinoma.



Papillary serous carcinoma

Peritoneal epithelioid mesothelioma




1/161, 4/452, 0/233, 5/134, 8/265, 14/456, 5/4017, 0/3619

3/31, 35/352, 28/323, 40/406, 15/1517


Useful but the positivity of some serous carcinomas makes this marker less than specific.


11/452, 5/233, 11/327, 9/265, 14/456, 11/4017

35/352, 17/323, 37/406, 14/1517

This marker is of limited value in this context.


7/208, 1/452, 6/233, 2/456, 2/4017

6/188, 26/352, 18/323, 29/406, 9/1517

Results vary between studies.


6/456, 98/16916, 8/4017

37/406, 14/1517

The evidence from these two studies is conflicting.


6/45 6

37/40 6

The specificity for mesothelioma is higher than that of calretinin but the sensitivity is lower.


25/309, 45/452, 3/610, 20/233, 45/456, 38/4017

4/352, 3/323, 5/406, 1/1517

Strong staining is a useful marker for serous carcinomas


47/4711, 33/4612, 37/4413, 13/2014, 10/1015, 27/309, 39/452, 33/456, 29/4017

0/2812, 3/1014, 0/2015, 0/352, 0/406, 0/1517

This marker has specificity for serous carcinomas but limited sensitivity.


34/4612, 32/4413, 6/2014, 8/1015, 17/309, 28/452, 7/233, 26/456, 18/4017

3/2812, 0/414, 3/2015, 0/352, 2/323, 0/406, 0/1517

This marker has specificity for serous carcinomas but low sensitivity.


44/452, 44/456

1/352, 2/406

This marker may be very helpful in this context, with a higher specificity than Ber-EP4.










No value



30/456, 24/4017

0/352, 0/406, 0/1517

This marker has specificity for serous carcinomas but low sensitivity.


42/452, 21/233

33/35, 8/323

Limited value


7/452, 2/233


No value, due to the low rate of positivity in serous carcinomas




No value, due to the low rate of positivity in serous carcinomas




No value




 No value




 No value




 No value




 No value






2/4017, 0/25518

15/1517, 1/5018

Conflicting results



0/1517, 2/171

Useful, based on one study





PAX2 24/3619 2/1719 Useful, based on one study
PAX8 253/25418 5/5018 Useful, based on one study

The optimum panel is probably BerEP4 and MOC-31 with calretinin, and D2-40 / podoplanin3,6. ER has been recommended as a marker for serous carcinomas and h-Caldesmon as a marker for mesotheliomas17.




Serous papillary carcinoma

Epithelioid mesothelioma



Straight microvilli of variable length, less prolific than in mesotheliomas and confined to the apical surface. Cell membranes are closely apposed. Intracytoplasmic lumina are absent.

Long slender branching microvilli. They may be confined to the apical surface, may also be present on the basal surface or may cover the entire cell membrane. Cells are separated by gaps that often contain microvilli. Microvilli may also be found on intracytoplasmic lumina.


 Bundles of intermediate fibres are rare.

The cytoplasm contains numerous intermediate filaments arranged in bundles.

Ciliated cells

Multi-ciliated cells may occur






1 Doglioni, C., Tos, A. P., Laurino, L., Iuzzolino, P., Chiarelli, C., Celio, M. R., Viale, G. Calretinin: a novel immunocytochemical marker for mesothelioma. Am J Surg Pathol1996;20:1037-46.

2 Ordonez NG. Role of immunohistochemistry in distinguishing epithelial peritoneal mesotheliomas from peritoneal and ovarian serous carcinomas. Am J Surg Pathol 1998; 22:1203-14

3 Attanoos RL, Webb R, Dojcinov SD, et al. Value of mesothelial and epithelial antibodies in distinguishing diffuse peritoneal mesothelioma in females from serous papillary carcinoma of the ovary and peritoneum. Histopathology 2002; 40:237-44

4 Cathro HP,Stoler MH. The utility of calretinin, inhibin, and WT1 immunohistochemical staining in the differential diagnosis of ovarian tumors. Hum Pathol 2005; 36:195-201

5 Chu AY, Litzky LA, Pasha TL, et al. Utility of D2-40, a novel mesothelial marker, in the diagnosis of malignant mesothelioma. Mod Pathol 2005; 18:105-10

6 Ordonez NG. The diagnostic utility of immunohistochemistry and electron microscopy in distinguishing between peritoneal mesotheliomas and serous carcinomas: a comparative study. Mod Pathol 2006; 19:34-48

7 Reis-Filho JS, Simpson PT, Martins A, et al. Distribution of p63, cytokeratins 5/6 and cytokeratin 14 in 51 normal and 400 neoplastic human tissue samples using TARP-4 multi-tumor tissue microarray. Virchows Arch 2003; 443:122-32

8 Attanoos RL, Appleton MAC, Goddard H et al. Thronmbomodulin expression in malignant peritoneal mesothelioma and serous papillary adenocarcinoma of the ovary. J Pathol 1995;176:S49A.

9 Rothacker D,Mobius G. Varieties of serous surface papillary carcinoma of the peritoneum in northern Germany: a thirty-year autopsy study. Int J Gynecol Pathol 1995; 14:310-8

10 Cherchi PL, Marras V, Capobianco G, et al. Immunohistochemical evaluation of a new epithelial antigen, Ber-EP4, in ovarian cancer: preliminary results. Eur J Gynaecol Oncol 2001; 22:433-5

11 Thor A, Gorstein F, Ohuchi N, et al. Tumor-associated glycoprotein (TAG-72) in ovarian carcinomas defined by monoclonal antibody B72.3. J Natl Cancer Inst 1986; 76:995-1006

12 Bollinger DJ, Wick MR, Dehner LP, et al. Peritoneal malignant mesothelioma versus serous papillary adenocarcinoma. A histochemical and immunohistochemical comparison. Am J Surg Pathol 1989; 13:659-70

13 Wick MR, Mills SE, Dehner LP, et al. Serous papillary carcinomas arising from the peritoneum and ovaries. A clinicopathologic and immunohistochemical comparison. Int J Gynecol Pathol 1989; 8:179-88

14 Khoury N, Raju U, Crissman JD, et al. A comparative immunohistochemical study of peritoneal and ovarian serous tumors, and mesotheliomas. Hum Pathol 1990; 21:811-9

15 Wick MR, Mills SE,Swanson PE. Expression of "myelomonocytic" antigens in mesotheliomas and adenocarcinomas involving the serosal surfaces. Am J Clin Pathol 1990; 94:18-26

16 Bassarova AV, Nesland JM,Davidson B. D2-40 is Not a Specific Marker for Cells of Mesothelial Origin in Serous Effusions. Am J Surg Pathol 2006; 30:878-82

17 Comin CE, Saieva C,Messerini L. h-caldesmon, calretinin, estrogen receptor, and Ber-EP4: a useful combination of immunohistochemical markers for differentiating epithelioid peritoneal mesothelioma from serous papillary carcinoma of the ovary. Am J Surg Pathol 2007; 31:1139-48

18 Laury AR, Hornick JL, Perets R, Krane JF, Corson J, Drapkin R, et al. PAX8 Reliably Distinguishes Ovarian Serous Tumors From Malignant Mesothelioma. Am J Surg Pathol. 2010 May;34(5):627-35.

19 Tong GX, Chiriboga L, Hamele-Bena D, Borczuk AC. Expression of PAX2 in papillary serous carcinoma of the ovary: immunohistochemical evidence of fallopian tube or secondary Mullerian system origin? Mod Pathol. 2007 Aug;20(8):856-63. FULL TEXT


This page last revised 29.4.2010.

©SMUHT/PW Bishop