Purpose: The size of a renal neoplasm is important for staging, prognosis and selection of appropriate treatment. Our aim was to determine whether there is a discrepancy between the radiographic and pathological size of renal tumors.
Patients and methods: The maximum size of 35 resected renal tumors was measured by computed tomography (CT) by 2 independent observers. The radiographic and pathological sizes were compared by size range and tumor radiological features.
Results: Although the radiographic and pathological size for all tumors was not statistically different (7.50 vs. 6.25 cm, p=0.452), the average radiographic size was larger than pathological tumor size in tumors smaller than 7 cm. Solid tumors showed more reduction in size (17.02%) compared with cystic and necrotic tumors (p=0.731). Only the radiographic size of ill-defined tumors was smaller than their pathological size (average 33.33%; p=0.865). The influence of tumor side (left or right kidney) and its location within the kidney did not influence the degree of decrease (p=0.147 and p=0.981, respectively).
Conclusion: A reduction in the size of renal tumors is observed in tumors<7 cm, which is explained by vasoconstriction during the temporary renal artery occlusion, surface hypothermia and blood loss during the operation. If this reduction of size is secondary to surgery, the radiographic size of renal tumors should be considered in staging and selecting the appropriate treatment for tumors<7 cm for which the decision of surgical approach depends on the size of the tumor.