Expression of Galectin-3 in renal neoplasms: a diagnostic, possible prognostic marker.

CONTEXT: Galectin-3, a member of the lectin family, was shown to be expressed in normal distal tubular cells and in renal cell carcinomas (RCC). However, its diagnostic and prognostic significance in RCC is as yet undefined.

OBJECTIVES: To describe the expression of Galectin-3 among different histologic subtypes of renal neoplasms and to determine their diagnostic and prognostic significances.

DESIGN: The expression of Galectin-3 was evaluated in 217 renal neoplasms by tissue microarray and immunohistochemistry with semiquantitative analysis.

RESULTS: Strong expression of Galectin-3 was observed in 92 of 217 of renal neoplasms (42.4%). Although 22 of 23 oncocytomas (95.7%) and 19 of 21 chromophobe RCCs (90.5%) express Galectin-3, only 4 of 32 papillary RCCs (12.5%) and 47 of 137 clear cell RCCs (34.3%) express Galectin-3, suggesting that it may be used as a potential diagnostic marker. Galectin-3 expression was seen in 55% of high-grade (Fuhrman nuclear grades 3 and 4) versus 21% low-grade (grades 1 and 2) clear cell RCCs (P < .001).

CONCLUSIONS: This study confirms that Galactin-3 is strongly overexpressed in renal cell neoplasms of distal tubular differentiation, that is, oncocytoma and chromophobe RCCs, suggesting it might be used as a possible differential diagnostic tool for renal cell neoplasm with oncocytic or granular cells. Furthermore, we observed a strong association of overexpression of Galectin-3 and high nuclear grade in clear cell RCC. These results also suggest a possible pivotal role for Galectin-3 in the differentiation and prognosis of clear cell RCC.