Comparison of the radiologic tumour size with the pathologic tumour size in renal cell carcinoma

Objective: This study aims to compare the radiologic tumour size (RTS) as measured by preoperative computerised tomography (CT) with the pathologic tumour size (PTS) as measured in a pathology specimen during the postoperative period for patients operated on due to renal tumours. Design: Retrospective study Setting: Samsun Training and Research Hospital, University of Health Sciences, Samsun, Turkey Subjects: One hundred and four patients who were operated on at our clinic due to renal tumours Intervention: The RTS is measured preoperatively using CT to determine the tumour's longest diameter, while the PTS is measured in a pathology specimen based on its longest diameter. Main outcome measure: The RTS and the PTS are compared in all the patients according to their histologic subtype and T stage. Results: For the 104 patients included in the study, the median RTS is 57.5 mm (range: 18 - 280 mm) and the median PTS is 52.5 mm (range: 12 - 280 mm), which is statistically significant (p = 0.009). According to the pathological staging for T1a tumours, the median RTS of 38 mm (range: 21 - 90 mm) and the median PTS of 30 mm (range: 12 - 40 mm) are determined to be statistically significant (p < 0.001). Conclusions: The preoperative CT measurement of the renal tumour is significantly higher than that of the pathology specimen, which may result in differences between clinical staging and pathological staging. It should be noted that a discrepancy between the RTS and PTS values can affect treatment selection for the patient.