[1002] Expression of HNF-1 in Ovarian Carcinomas with Clear Cells

YC Kao, MC Lin, TL Mao. National Taiwan University Hospital, Taipei, Taiwan

Background: Hepatocyte nuclear factor-1 (HNF-1) is a transcription factor essential during the embryonic development of liver, kidney, pancreas and Mullerian duct. It was found to be overexpressed in ovarian clear cell carcinoma by cDNA microarray. The specific expression was confirmed by immunohistochemistry. However, the expression of HNF-1 in ovarian carcinomas with clear cells has not been addressed. To clarify if the expression of HNF-1 is specific for clear cell carcinoma but not in other ovarian carcinomas with clear cells, we studied the expression of HNF-1 in various ovarian carcinomas with clear cells.
Design: Archival HE slides of ovarian carcinomas diagnosed during 1996 to 2004 were reviewed. The study material included 40 ovarian clear cell carcinomas, 20 high grade serous carcinomas and 20 endometrioid carcinomas containing clear cells, and 13 ovarian carcinomas originally diagnosed as mixed endometrioid and clear cell carcinoma. The expression of HNF-1 was studied by immunohistochemistry on representative paraffin sections.
Results: HNF-1 was positive in all 40 clear cell carcinomas. The expression was usually diffuse and strong irrespective of the pattern and the amount of clear cytoplasm. In two tumors also containing areas of poorly differentiated carcinoma, the expression of HNF-1 was weak in the poorly differentiated area. Only one endometrioid carcinoma and two high grade serous carcinomas were positive for HNF-1. The staining was weak and patchy in the two high grade serous carcinomas. In the 13 mixed endometrioid and clear cell carcinoma, HNF-1 was diffusely and strongly positive in the clear cell component in ten of the cases. The endometrioid components were negative in five and weakly positive in the other five.

In the three cases negative for HNF-1, the clear cell components were arranged in solid or glandular pattern, randomly mixed with the typical endometrioid carcinoma. Correlating with the negativity of HNF-1, they may represent endometrioid carcinomas with clear cell change.
Conclusions: Our results showed that the expression of HNF-1 in ovarian carcinoma is highly specific for clear cell carcinoma. Combining histomorphology and expression of HNF-1, the diagnosis of ovarian carcinomas with clear cells can be made with higher accuracy.
Category: Gynecologic

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 154, Monday Morning