HISTOLOGICAL EVALUATION OF ENUCLEATION FOR RENAL CELL CARCINOMA USING RADICAL NEPHRECTOMY SPECIMENS

Abstract

Radical nephrectomy was performed in 30 cases of renal cell carcinoma in which CT scan and angiography findings had indicated the possible suitability of enucleation. The lesions were then enucleated from the operative specimens and assessed histologically to find the feasibility of tumor enucleation and to determine its indications. Histological investigation demonstrated that the tumor was completely surrounded by the pseudocapsule in only 17 cases, and even in such tumors the thickness of the pseudocapsule was not always regular and sometimes tumor invasion was seen in the pseudocapsule. It is therefore advisable to resect the tumor with no less than several mm of surrounding renal tissue when the pseudocapsule can not be clearly distinguished.
Success of the enucleation was confirmed histologically in 22 out of 30 cases (73.3%). The factors related to failure of the enucleation were invasion throughout the renal capsule in 2, tumor exposure on the resected surface in 5, residual tumor in the tumor bed in 2 and venous invasion in 6 cases. Satellite tumors were not detected in any case. Favorable results were obtained in low grade, low stage tumors less than 6cm in diameter and clearly distinct from normal renal tissue, therefore such cases were thought to be appropriate indications for enucleation.
Although we selected the cases thought to be appropriate for enucleation by imaging techniques preoperatively, success was not obtained in all cases. Enucleation is a useful and recommendable operative technique for bilateral renal cell carcinoma or renal cell carcinoma in a solitory kidney. However, surgical enucleation does not always result in curative resection and therefore it should not be selected when the contralateral kidney is normal.