INTRAOPERATIVE EVALUATION OF RENAL-CELL CARCINOMA - A PROSPECTIVE-STUDY OF THE ROLE OF ULTRASONOGRAPHY AND HISTOPATHOLOGICAL FROZEN-SECTIONS

Purpose: Nephron sparing surgery is being performed increasingly for t reatment of renal cell carcinoma, including in select patients with a normal contralateral kidney. The number of tumors in the involved kidn ey (single versus multiple) and presence or absence of perinephric fat involvement (pathological stage T1 to 2 versus T3A) are important pro gnostic factors. In a prospective study we evaluated the accuracy of i ntraoperative histopathological frozen section analysis of renal capsu lar biopsies for assessing local tumor stage, and the accuracy of intr aoperative ultrasonography for assessing tumor focality. Materials and Methods: Intraoperative frozen section biopsies and ultrasonography w ere compared with information obtained from preoperative computerized tomography (CT), intraoperative inspection of the kidney by the surgeo n and permanent histopathological specimens. Results: We evaluated 99 patients (102 kidneys) with localized solid renal masses undergoing ei ther radical nephrectomy (48) or nephron sparing surgery (54). Final p athological analysis revealed 95 renal cell carcinomas (stage T3A in 2 4), 6 oncocytomas and 1 angiomyolipoma. Multiple tumors were detected in 18 of 102 kidneys overall. Frozen section analysis identified 87% o f the stage T3A lesions with no false-positive results, compared to CT , which only identified 67%. Ultrasonography identified 14 of 18 multi focal tumors (78%) and was not more accurate than the combination of C T and intraoperative inspection. However, during nephron sparing surge ry ultrasonography was useful to localize the intrarenal extent of tum ors (17 cases). Conclusions: Our results clarify the role of intraoper ative ultrasonography and frozen section analysis in patients undergoi ng nephron sparing surgery for renal cell carcinoma. Frozen section an alysis may be useful in select patients with small peripheral tumors w ho are under consideration for elective nephron sparing surgery.