[722] Renal Cell Carcinoma Associated with Prominent Leiomyomatous Proliferation Appears Not To Be a Variant of Clear Cell Renal Cell Carcinoma

M Brunelli, F Menestrina, D Segala, R Tardanico, S Gobbo, M Chilosi, L Barzon, S Zhang, L Cheng, JN Eble, G Martignoni. Universit di Verona, Verona, Italy; Universit di Brescia, Brescia, Italy; Universit di Padova, Padova, Italy; Indiana University, Indianapolis

Background: A few renal cell carcinomas composed of epithelial elements resembling clear cell and stromal elements with angioleiomyoma-like and leiomyomatous features have recently been described. The aim of this study is to investigate the immunohistochemical and molecular profile of three additional cases of these tumors and to evaluate their relationship with clear cell renal cell carcinoma.
Design: Immunohistochemistry was performed on the tumors with antibodies to detect CD10, cytokeratin 7 (CK7), high molecular weight cytokeratin 34bE12, aacemase (AMACR), S100A1, parvalbumin, HMB45, desmin, -smooth muscle actin (-SMA) and caldesmon. Interphase fluorescence in situ hybridization analysis was performed with a centromeric probe for chromosome 3 and a subtelomeric probe for 3p25 in order to evaluate 3p deletion.
Results: The epithelial elements in all three tumors showed positive reactions for CD10, CK7 and S100A1. Two tumors were positive for 34bE12. All of the other markers gave negative reactions in the epithelial components. The stromal elements displayed strong immunoreactivity for -SMA and caldesmon. The clear cell component did not show 3p deletion.
Conclusions: We concluded that: 1) renal cell carcinomas associated with prominent leiomyomatous proliferation show immunoreactivity for CK7 and 34bE12 which usually are not present in clear cell renal cell carcinoma; 2) the epithelial elements do not show the 3p deletions typical of clear cell renal cell carcinoma; 3) the results suggest the epithelial elements in renal cell carcinoma associated with prominent leiomyomaotus proliferation are not a variant of clear cell renal cell carcinoma.
Category: Genitourinary (including renal tumors)

Tuesday, March 10, 2009 1:30 PM

Platform Session: Section A, Tuesday Afternoon