Lectin histochemical studies on renal tumors.

Histochemical characteristics on lectin binding of 16 cases of nephroblastoma and of 57 cases of renal cell carcinoma were studied on those of six embryonal and fetal kidneys in 4 to 24 gestational weeks and in six normal adult kidneys using four biotinylated lectins (PNA, LTA, SBA and UEA-1), which show segment specific binding for normal nephron. In normal nephrogenesis, Gal beta 1-3 GalNAc (PNA receptor) appeared at first in developing tubuli of the metanephros at 10 gestational weeks, and remained positive in proximal tubuli of 13 gestational weeks, where the Lewis X antigen (LTA receptor) emerged. In adult kidneys, Gal beta 1-3 GalNAc distributed along distal tubuli and collecting ducts and not in proximal tubuli. Type 2 H antigen (UEA-1 receptor) was confined to collecting ducts. In nephroblastomas, positive reaction to these lectins were almost exclusively confined to tubular structures. Gal beta 1-3 GalNAc was constantly positive there. Intensely positive stain of Lewis X antigen was observed in three cases of histologically well differentiated type. Lewis X antigen positive tubuli co-expressed Gal beta 1-3 GalNAc. There were six type 2 H antigen positive cases showing differentiation toward ureteric bud or collecting ducts. In view of the cell surface glycosylation, regular differentiation of fetal renal tubuli was also retained in nephroblastomas according to their degree of histological differentiation. In renal cell carcinoma, Gal beta 1-3 GalNAc was positive in 49% (28/57) and Lewis X antigen was positive in 54% (31/57). Type 2 H antigen was completely negative. In contrast to the nephroblastoma, there was no correlation between histological features and lectin binding patterns in renal cell carcinoma.