Objectives: To critically appraise and determine the impact of image-guided biopsy on the management of indeterminate renal masses. A comparison of long-term follow-up of renal cell carcinoma (RCC) diagnosed by image-guided biopsy and radiologically obvious RCC was also carried out.
Patients and methods: Data were collected for all the consecutive patients requiring renal core biopsies for the diagnosis of indeterminate renal masses between January 1996 and January 2006. The long-term outcome of diagnostic and nondiagnostic renal biopsies was assessed. Furthermore, the long-term outcome of RCC diagnosed following biopsies was compared with nonbiopsy radical nephrectomy done during the same time period.
Results: Of the 70 biopsy procedures performed, 9 were nondiagnostic and 61 were diagnostic on histopathologic examinations (17 benign and 44 malignant). The histopathology of all radical nephrectomies was identical to the pathology of biopsy specimens. Of the nine nondiagnostic cases, one patient had a repeat biopsy that was confirmed as RCC. Six patients including the case diagnosed to have RCC on repeat biopsy underwent radical nephrectomy in the nondiagnostic group. The histopathology revealed RCC in four, and angiomyelolipoma and pyelonephritis in one each. The remaining three nondiagnostic cases are under follow-up; there has been no change in the size of the lesions in a mean follow-up of 32 mo (range: 12-52). There has been no change in the size of benign lesions at a mean follow-up of 29 mo (range: 3-72). The procedure-related complication in the form of bleeding following biopsy was observed in one patient, which settled conservatively. There was no statistically significant difference (chi-square=1.134 and p value equal to 0.379) in the recurrence rate and metastases between the biopsy radical nephrectomy and nonbiopsy radical nephrectomy groups for the same stage of disease during the same period.
Conclusions: Image-guided biopsy is safe and accurately characterises indeterminate renal masses. A repeat biopsy protocol is useful in case of a nondiagnostic first biopsy. The long-term outcome following radical nephrectomy of biopsy-diagnosed RCC does not differ from the radiologically obvious RCC.