OBJECTIVE

To define the accuracy and acceptability of ultrasonography-guided percutaneous needle core biopsy in diagnosis of renal masses.

METHODS

The data of 42 consecutive patients on whom needle biopsies were performed and were surgically treated for suspicious renal masses in our clinic between January 2001 and April 2008 were evaluated. In all patients, needle biopsies were done percutaneously with an 18-gauge needle under local anesthesia in prone position with ultrasonography guidance. Two cores were taken from each tumor. The pathology results of biopsy and surgical specimens were compared.

RESULTS

The mean age was 56.1 years (range, 21-77 years). The mean follow-up period was calculated as 44.8 months (range, 10-85 months). The abdominal computed tomography imaging showed that the mean mass size was 63.9 mm (range, 25-140 mm). Of 42 patients, 39 were diagnosed (92.8%) after the first biopsy. The accuracy of percutaneous needle biopsy in differentiating between malignant and benign masses was calculated as 90% (36/40).The accuracy of histopathological diagnostic typing as against the postsurgical pathologic examination results was 77.5% (31/40) and the accuracy in the Fuhrman grade was 51.5% (17/33). The sensitivity was calculated as 91.4% and specificity as 60%. Its negative predictive value was 50% and positive predictive value was 94.1%.

CONCLUSIONS

In conclusion, percutaneous renal needle core biopsy has an acceptable sensitivity and specificity in the diagnosis of renal masses. The major limitation of percutaneous core biopsy is the technical failure that leads to insufficient material for accurate diagnosis.