[793] Study of Useful Markers for Differential Diagnosis of Non-Clear Cell Type Renal Cell Carcinoma Including Papillary Renal Cell Carcinoma, Chromophobe Renal Cell Carcinoma, and Xp11 Translocation Carcinoma

A-R Kim, W-J Sung, J-M Kim, M-J Kim. Yeungnam University Hospital, Daegu, Republic of Korea

Background: Renal cell carcinoma represents over 90% of all malignancies of the adult kidney. This tumor is a morphologically and genetically heterogeneous tumor. Although clear cell tumor type is the most frequent and usually not difficult to make diagnosis, other histologic subtypes of renal cell carcinoma, such as papillary, chromophobe, and Xp11 translocation carcinoma, can be encountered in practice and sometimes differentiation between them is difficult. In this study we tried to do immunohistochemistry for the diagnosis of these tumors.
Design: 55 cases of renal cell carcinomas (30 of clear cell type, 12 of papillary type, 7 of chromophobe type, 6 of Xp translocation carcinoma) were obtained at Yeungnam University Hospital from Jan. 2005 to July 2008. Immunohistochemistry using E-caderin, beta-catenin, PTEN, EGFR, gaelctin-3, and TFE3 was done on tissue microarray slide. The staining reaction was classified according to a semi-quantitative reference scale ranging from 1 to 3+.
Results: Papillary subtype showed 90% positivity for beta-catenin and PTEN, while clear cell subtype revealed average 20% positivity for E-cadherin and PTEN. 6 and 7 cases out of 7 chromophobe subtype were significantly strong staining pattern in E-cadherin and galectin-3, respectively (p<0.01). All of 6 Xp11 translocation carcinoma showed overexpression of EGFR protein (p<0.001), even though TFE3 positivity was present in 3 cases. TFE3 expression was also noted in some of papillary and clear cell renal cell carcinoma.
Conclusions: Expression of galetin-3 was very useful in diagnosis of chromophobe renal cell carcinoma. Xp11 translocation carcinoma revealed more specific expression of EGFR than TFE3. It is likely that TFE3 expression may not specific to translocation carcinoma.
Category: Genitourinary (including renal tumors)

Tuesday, March 10, 2009 9:30 AM

Poster Session III # 78, Tuesday Morning