[1145] IMP3 Expression Differentiates Ovarian Serous from Endometrioid Carcinoma

Steven Goodman, Di Lu. Umass Memorial Medical Center, Worcester, MA

Background: Ovarian carcinoma is characterized by a wide range of tumors. Histologically, differentiation of serous from endometrioid carcinoma can sometimes be difficult, and so far there is no reliable biomarker available. The aim of this study was to compare the expression pattern and diagnostic value of IMP3 in endometrioid and serous carcinomas of the ovary.
Design: A total of 84 cases (endometrioid carcinoma, n=10; serous carcinoma, n=74) obtained from the surgical pathology files of Umass Memorial Medical center were examined by immunohistochemistry for IMP3 expression. The epithelial/tumor cell staining with IMP3 was recorded by percentage for each lesion. Expression in more than 15% of tumor cells is a positive result.
Results: IMP3 showed dark brown cytoplasmic staining (see figure 1). IMP3 expression was positive in 1/10 (10%, median 5% staining) of endometrioid carcinoma cases, and positive in 57/74 (77%, median 80% staining) of serous carcinomas (see figure 2).

Conclusions: IMP3 is expressed in majority of serous carcinoma but only rarely in endometrioid carcinoma. Positive IMP3 staining can increase the level of confidence in differential diagnosis of endometrioid vs. serous carcinoma.
Category: Gynecologic & Obstetrics

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 196, Tuesday Morning


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