Prospective analysis of computerized tomography and needle biopsy with permanent sectioning to determine the nature of solid renal masses in adults

Purpose: We prospectively determined the accuracy of computerized tomography (CT) and needle biopsy of solid renal masses. Materials and Methods: A total of 100 patients with a solid renal mass who were scheduled for operation were prospectively evaluated. CT was performed before radical or partial nephrectomy. Biopsy of the surgical specimens was done twice through the tumor using an 18 gauge biopsy gun. Specimens were sent for permanent section and review by 2 pathologists blinded to each other and to the whole tissue specimens. Images were reviewed by 2 radiologists blinded to each other and to the results of pathological analysis. Results of CT and permanent biopsy were compared with the results of whole tissue specimen analysis. Results: Specimens were obtained from 59 radical and 41 partial nephrectomies. Malignant neoplasms were present in 85 patients (85%). Overall accuracy was 77% and 72%, the nondiagnostic rate was 20% and 21%, sensitivity was 81% and 83%, and specificity was 60% and 33%. For the 2 radiologists overall accuracy was 60% and 66%, the nondiagnostic rate was 31% and 23%, sensitivity was 70% and 77%, and specificity was 20% and 20%, respectively. Conclusions: Overall permanent biopsy results were accurate in more than 72% of cases and CT was accurate in more than 60%. However, because the nondiagnostic rate for CT and needle biopsy was 20% and 31%, respectively, and specificity was low, we do not recommend routine preoperative CT and subsequent needle biopsy to guide treatment decision making. Rather, cases must be decided individually.