Incidental renal tumours: the frequency of benign lesions and the role of preoperative core biopsy

Abstract

OBJECTIVE To determine the incidence of benign renal lesions in incidentally discovered small renal tumours, increasingly detected by the widespread use of abdominal imaging, and to evaluate whether preoperative renal core biopsy is effective in identifying benign lesions. MATERIALS AND METHODS In a retrospective study, renal core biopsies for incidental tumours over a 5‐year period were analysed. The biopsies were correlated with the final pathology of the nephrectomy specimens, or with patient follow‐up if nephrectomy was avoided. RESULTS Of 70 diagnostic core biopsies, a third of cases were considered benign. The sensitivity and specificity for both benign and malignant lesions when compared to definitive pathology was 100% in all cases subjected to nephrectomy. Of the 30 non‐diagnostic biopsies, three were proved to be benign, and 18 likely to be benign. The only complication of renal biopsy was one case of bleeding after biopsy. CONCLUSION A higher than previously anticipated proportion of incidentally detected small renal masses are benign. Given the high sensitivity and specificity, there is value in taking a core biopsy of small incidental renal lesions, a procedure with a low complication rate (1%). When analysed by a pathologist familiar with renal biopsy, this might avoid radical nephrectomy in many patients.

Diagnostic Accuracy and Risks of Biopsy in the Diagnosis of a Renal Mass Suspicious for Localized Renal Cell Carcinoma: Systematic Review of the Literature

“…There were 15 core biopsy studies that used 18G needles. 5,13,15,16,18,20,21,[23][24][25][26][27][28][29][30] Eleven studies included biopsies performed using multiple imaging modalities (primarily CT or ultrasound). Radiation exposure from CT guidance occurred in 44.3%.…”

“…2). 5,[12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] One evaluated FNA with cytopathology alone 12 and all other studies evaluated core needle biopsy with surgical pathology. There were 15 core biopsy studies that used 18G needles.…”

“…Overall 3,074 tumors were biopsied, with 11 studies focused specifically on localized clinical T1a tumors 5,13,14,16,[18][19][20][21][22]26,27 and another 3 focused on tumors 5 cm or smaller. 12,23,25 Among these studies mean tumor size ranged from 2.3 to 3 cm (supplementary table 2, http://jurology.com/).…”

“…12,24,28,29 Ten included consecutively performed biopsies. 5,12,20,21,[23][24][25][26]28,29 Overall 9 were performed in North America, 5,12,[14][15][16][17]26,27,30 5 in Europe, 13,19,20,28,29 and 3 each in Asia 21,22,24 and Australia. 18,23,25 One study was an update 23 of a previously published series.…”

Natural History and Management of Small Renal Masses

“…Vasudevan et al reported a 33% benign histology in 70 renal masses smaller than 5 cm 5 . Similarly, a report of 100 laparoscopic partial nephrectomies for a mean tumour size of 2.9 cm showed that 32% of the surgeries were performed for benign disease, as indicated by the final pathology specimen 6 .…”