QUANTITATIVE ASSESSMENT OF VASCULAR SURFACE-DENSITY IN RENAL-CELL CARCINOMAS

Objective To evaluate the extent of a vascularization by assessing vas cular surface density in renal cell carcinomas (RCCs) of different nuc lear grades, and in normal renal cortex and medulla. Materials and met hods Specimens of 79 RCCs of different nuclear grades (16 of G1, 42 of G2 and 21 of G3) were immunostained with the lectin UIex europaeus ag glutinin-I (UEA I). The vascular surface density of tumour tissue was assessed stereologically using a test grid at x400 magnification and c ompared to the values obtained in normal renal tissue. Results G3 tumo urs had a lower vascular surface density than had G1 and G2 RCCs and n ormal renal tissue of the cortex and medulla (P<0.001, respectively). G1 tumours had a significantly higher vessel density than had normal m edullary parenchyma and G2 carcinomas (P<0.001), Vessel density was no t significantly different among G1 tumours and cortical parenchyma in controls and among normal medullary tissue and G3 tumours, Statistical analysis showed that the vascular surface density was independent of tumour stage and size and the age and sex of the patients. Conclusion The degree of vascularization in RCCs decreased with their grade of di fferentiation, suggesting that the extent of neovascularization in tum our tissue reflects the relationship between tumour cell proliferation and vascular growth. The values of vascular surface density in normal renal tissue of the cortex and medulla partially overlapped with thos e obtained in tumour tissue.