Lectin staining of renal cell tumours with special emphasis on oncocytomas

There are conflicting results respecting the segmental tubular origin of renal oncocytomas, a type of tumour said to be highly differentiated and benign, though metastases have been described. The aim of this study was, by applying different lectins on renal cell carcinomas (n = 50) and oncocytomas (n = 12), to search for patterns which could indicate a specific segmental origin of oncocytomas and perhaps elucidate the differentiation of this tumour. The following lectins were applied: jacalin, peanut agglutinin (PNA), wheat germ agglutinin (WGA), phytohemagglutinin E (PHA-E), concanavalin A (Con A), and Dolichos biflorus agglutinin (DBA). The results show that oncocytomas are positive when jacalin, a Lectin that stains distal tubules and collecting tubules, is used, supporting the view that the tumour derives from distal or collecting tubules. The staining of the oncocytomas is generally polarized as in normal kidney tubules underlining that the tumour is highly differentiated. Two oncocytomas with aggressive behaviour showed areas with a diffuse pattern suggesting lower differentiation.