[875] Hepatocyte Nuclear Factor-1 Beta Expression in Clear Cell Adenocarcinomas of the Bladder and Urethra

PB Illei, J Epstein, M Herawi, R Sharma, F Brimo. Johns Hopkins Medical Institutions, Baltimore, MD; Wayne State University, Detroit, MI

Background: Hepatocyte nuclear factor-1beta (HNF-1beta) has been recently reported to be commonly overexpressed in clear cell tumors and endometriosis of the ovary and uterus. We sought to study the expression of HNF-1beta in a series of clear cell adenocarcinomas (CCA) of the bladder/urethra.
Design: Seventeen (17) cases of CCA of the bladder and urethra where unstained slides were available were included. Immunohistochemical stains for HNF-1beta were performed on paraffin-embedded sections using a polyclonal goat antibody. A case was considered positive if ≥10% of the tumor cells showed nuclear staining. Staining intensity was calculated using a three tiered-grading system (weak, moderate, strong).
Results: Of the 17 cases included 14 were part of the consultation files of one of the authors (J.E.). The site of origin was bladder (n=9) and urethra (n=8). Specimens included biopsy (n=5), transurethral resection (n=5), and total resection (n=7) material. The mean age was 62.5 years (range=36-91) and the female to male ratio was 4.7:1. All 17 cases were positive with 15 cases showing strong, one case showing moderate and one case showing weak nuclear staining. In all cases the number of positive tumor cells exceeded 90%.
Conclusions: Our findings have both diagnostic and histogenetic implications. HNF-1beta cannot be used to differentiate CCAs of ovary/uterus from bladder/urethra origin due to the frequent expression in both. We are in the process of studying the expression of HNF-1 beta in TMAs of nephrogenic adenoma and enteric adenocarcinomas of the bladder to determine if HNF-1 beta will have further diagnostic utility. From the histogenetic standpoint, there has been controversy whether CCA of the bladder/urethra is related to urothelial or müllerian origin. The expression of HNF- beta in both ovary/uterus and bladder/urethra CCAs provides evidence for a müllerian relationship, although a urothelial association cannot be excluded.
Category: Genitourinary (including renal tumors)

Tuesday, March 23, 2010 1:00 PM

Poster Session IV # 88, Tuesday Afternoon


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