Correlation between size of renal cell carcinoma and its grade, stage, and histological subtype

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