RESUMEN
The aim of this study was to determine the correlation between histological subtype, size, grade, and stage of the kidney tumors and to investigate whether a correlation exists between the size of the kidney tumor and its behavior. Between 1996 and 2004, we had 212 patients with radical or partial nephrectomy due to a kidney tumor at Shaheed Labbafmejad Medical Center. Their pathologic blocks were re-evaluated with consideration of their tumor size and pathologic features. Of 212 pathologic blocks, 17 [8%] were benign and 195 [92%] were malignant masses including 179 renal cell carcinoma [RCC] tumors. Malignant tumors were slightly greater compared with the benign ones [P = .10]. There was no significant relation between the size of tumor and the histological subtype. Significant relations between the size of the kidney tumor and the nuclear grade [P = .007], clinical symptoms [P = .02], and extracapsular extension [P < .001] were observed. In smaller RCC tumors [< 4 cm], extracapsular extension [stages T3 and T4] was rare [1 in 29]. However, smaller RCC tumors were not significantly different from those larger than 4 cm regarding the nuclear grade, symptoms, and histological subtypes. Tumor size is not an independent predictor for the histological subtype of the tumors; however, larger malignant tumors may have higher grades, higher stages, and clinical symptoms