Evaluation of Putative Renal Cell Carcinoma Markers PAX-2, PAX-8, and hKIM-1 in Germ Cell Tumors (GCT): A Tissue Microarray Study of 100 Cases.
Ankur Sangoi, John Higgins, James Brooks, Joseph Bonventre, Jesse McKenney. Stanford University Medical Center, CA; Harvard Medical School, Boston, MA
Background: Within the spectrum of genitourinary neoplasia, metastatic GCT and renal cell carcinoma may show morphologic overlap. Expression of putative renal cell carcinoma markers PAX-2, PAX-8, and hKIM-1 have been reported in a few GCT, which have included mostly seminoma (PAX-8) and yolk sac tumor (PAX-2, PAX-8, hKIM-1); however, a thorough characterization of staining by GCT subtype within a large series has not been previously reported.
Design: Immunohistochemical expression of PAX-2, PAX-8, and hKIM-1 was evaluated in 100 GCTs using tissue microarray technology (in triplicate) with standard avidin-biotin technique. Normal renal cortex and clear cell renal cell carcinoma were used as control tissues. Positive reactivity was scored as nuclear (PAX-2, PAX-8) or membranous/cytoplasmic (hKIM-1).
Results: Of the 100 GCT evaluated [including choriocarcinoma (1), embryonal carcinoma (21), intratubular germ cell neoplasia unclassified (2), seminoma (61), spermatocytic seminoma (1), teratoma (5), and yolk sac tumor (8)], expression for hKIM-1 was identified in 48% of embryonal carcinomas and 50% of yolk sac tumors (weak to strong in both tumors). PAX-2 and PAX-8 reactivity was identified in 50% and 25% of yolk sac tumors, respectively.
Conclusions: While this study confirms PAX-2/PAX-8/hKIM-1 reactivity in yolk sac tumor as previously noted from a smaller series by our group. This study also demonstrates hKIM-1 reactivity in embryonal carcinoma, supporting the notion that these putative renal cell carcinoma markers should be used cautiously.
Category: Genitourinary (including renal tumors)
Tuesday, March 1, 2011 1:00 PM
Poster Session IV # 80, Tuesday Afternoon