p53 immunohistochemistry for distinguishing reactive mesothelium from low grade ovarian carcinoma.
OBJECTIVE
To determine the utility of immunohistochemical staining for p53 in cell block material for distinguishing reactive mesothelium from borderline or low grade ovarian carcinoma.


METHODS
Paraffin-embedded cell blocks from paracentesis and pelvic wash fluid of 44 cases of ovarian carcinoma and 20 cases containing only reactive mesothelium were immunostained for p53 using monoclonal antibody DO-7. Tumor grades ranged from borderline to high grade and were serous papillary (33), clear cell (3), mucinous (2), endometrioid (2), mixed serous papillary/clear cell (3) and undifferentiated (1). The three authors independently evaluated the staining, including estimation of the percentage and intensity of positive nuclear staining.


RESULTS
A separation of positive from negative cases was seen when staining intensity was considered the critical parameter; moderate to strong staining was considered truly positive. Seventy-three percent (8/11) of borderline tumors, 80% (8/10) of low grade tumors and 65% (15/23) of intermediate to high grade tumors showed moderate to strong positivity. Percentage of staining was a less-reliable parameter as 25% of negative cases were positive by this assessment.


CONCLUSIONS
p53 Immunohistochemistry, using monoclonal antibody DO-7 combined with standard morphologic evaluation, may be useful in distinguishing benign reactive mesothelium from borderline or low grade ovarian carcinoma.
Pindzola
J A
JA
Department of Pathology, Cell Biology and Anatomy, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Kovatich
A J
AJ
Bibbo
M
M
D000911:Antibodies, Monoclonal; D001202:Ascitic Fluid / Q000737:chemistry*; D002277:Carcinoma / Q000737:chemistry* / Q000473:pathology; D002467:Cell Nucleus / Q000378:metabolism / Q000473:pathology; D003581:Cytodiagnosis / Q000379:methods; D004847:Epithelial Cells / Q000737:chemistry*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D010051:Ovarian Neoplasms / Q000737:chemistry* / Q000473:pathology; D012680:Sensitivity and Specificity; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
D000911:Antibodies, Monoclonal; D016159:Tumor Suppressor Protein p53