The current role of percutaneous needle biopsies of renal tumours.
The role of percutaneous biopsy of renal masses has been traditionally limited by concerns about its safety, accuracy and sampling errors. The increasing incidence in the diagnosis of incidental small renal masses (SRMs), the development of conservative and minimally invasive treatments for low risk renal cell carcinomas (RCCs) and the discovery of novel targeted treatments for metastatic disease are now leading to wider indications for renal tumor biopsy. Percutaneous biopsy of renal tumors can be performed in an outpatient setting under ultrasound and/or CT guidance. 18 gauge needles loaded in an automatic biopsy gun are used to retrieve cores and 21 gauge needles to obtain FNA specimens through a 17 gauge coaxial cannula placed close to the tumor. A careful check of the quality of biopsies and aspirates is paramount to maximize the diagnostic yield of the procedure. With the development of new biopsy techniques the risk of tumor seeding appears negligible and significant bleeding is unusual and very rarely clinically significant. In centres with expertise, needle core biopsy with or without FNA can provide adequate specimens for an accurate diagnosis in over 90% of cases. Incidental SRMs are frequently detected in elderly patients and have a very heterogeneous biological behaviour At surgery up to one third have benign histologies and most of those that are malignant are low grade RCCs. Pretreatment percutaneous biopsy can significantly decrease the number of unnecessary surgeries for benign disease and assist the urologist in clinical decision making, especially for elderly and unfit patients who are possible candidates for active surveillance and/or minimally invasive ablative therapies. Finally, there is potential for stratifying initial therapy of metastatic RCC by histological subtype on needle biopsies.
Volpe
Alessandro
A
Division of Urology, Maggiore della Carità Hospital, University of Eastern Piedmont, Novara, Italy. alessandro.volpe@med.unipmn.it
Terrone
Carlo
C
Scarpa
Roberto M
RM
D044963:Biopsy, Fine-Needle / Q000379:methods; D001707:Biopsy, Needle / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D006470:Hemorrhage / Q000517:prevention & control; D006801:Humans; D033162:Incidental Findings; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D009366:Neoplasm Seeding; D009367:Neoplasm Staging; D009392:Nephrectomy / Q000379:methods; D011237:Predictive Value of Tests; D011379:Prognosis; D015641:Radiography, Interventional; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional