[996] IMP3 Staining of Serous Carcinomas and Endometrioid Carcinomas

R Jaffar, Z Jiang, D Lu. UMass Memorial Medical Center, Worcester, MA

Background: Serous carcinoma (SC) or Endometrial type II carcinoma is an aggressive tumor. Because of difficulty in determining a morphologically evident precursor and lack of biological markers, a precursor lesion has not been identified yet. Insulin like growth factor mRNA-binding proteins (IMP1, 2, and 3), are oncofetal proteins expressed during embryogenesis and in malignant tumors. IMP3 expression has been studied in Serous Carcinoma (SC) and Endometrioid carcinoma (EC). The aim of our study is to detect IMP3 expression in precursor dysplastic epithelium of SC.
Design: We reviewed 99 cases of surgical resections from our surgical pathology archives which comprised of 16 SC, 57 EC, and 26 mixed carcinomas. H and E slides were selected with both tumor (glands and surface epithelium) and adjacent normal (glands and surface epithelium) tissue. Immunohistochemistry was performed on formalin fixed sections using monoclonal antibody to IMP3. Staining was scored on a scale of 0 to 3+ in the tumor and adjacent normal endometrium. Statistical significance was evaluated using the Chi-Square test with Yates' correction.
Results: Of the16 SC, 11 (78.6%) showed positive surface epithelial staining and 13 (81.2%) showed positive glandular staining.

Of the 57 EC, none showed epithelial but 9 (15.8%) showed glandular staining. SC showed more staining in the surface epithelium as compared to EC (p value=0.0001). In the mixed carcinomas, SC epithelial component showed more staining when compared to EC epithelial component (p value=0.0081). On comparing the staining in SC from both pure and mixed tumors, no difference was found (p value=0.5828). A significant difference was found on comparing the staining in EC from pure and mixed tumors (p value=0.0001). The staining character in EC of mixed tumors was focal and 1+ to 2+. Overall comparison between SC and EC of both pure and mixed forms showed a significant difference for staining (p value=0.0001).
Conclusions: Differential IMP3 staining in the surface epithelium of SC might aid in recognition of early changes of SC. Significant difference in staining for EC in pure and mixed tumors suggests a difference in biology and perhaps behavior. Further study to validate the use of IMP3 for detection of precursor lesions is being undertaken.
Category: Gynecologic

Wednesday, March 11, 2009 1:00 PM

Poster Session VI # 151, Wednesday Afternoon