[861] The Diagnostic Accuracy and Clinical Role of Percutaneous Renal Needle Core Biopsy in Renal Cortical Neoplasms

Lan L Gellert, Rohit Mehra, Ying-Bei Chen, Anuradha Gopalan, Samson Fine, Hikmat Al-Ahmadie, Victor E Reuter, Satish Tickoo. Memorial Sloan-Kettering Cancer Center, New York, NY

Background: The role of renal needle core biopsy in the management of renal cortical neoplasm remains controversial. In a prior ex vivo study, in combination with immunohistochemistry (IHC), we determined the diagnostic accuracy of this procedure. In the present study, we report our experience with in vivo renal needle core biopsies (NCB), and its impact on clinical management.
Design: We identified 217 consecutive cases of percutaneous NCB for renal masses performed at our institution between 2006 and 2011. All pathology reports, H&E and IHC slides were reviewed. Clinical data were collected from patient charts.
Results: Of the 217 cases, 178 showed neoplastic and 39 benign tissue. Of these 39 cases, 11 were performed for evaluation of the cryoablation bed, 3 were proven to be inflammation/infection, and 25 were neoplasms. In the 178 cases in which a neoplasm was identified, the diagnosis was: 80 clear cell renal cell carcinoma (CCRCC), 27 low grade (LG) oncocytic neoplasms (9 oncocytoma, 9 chromophobe (CHR-RCC) and 9 NOS), 7 papillary RCC (PRCC), 4 clear cell papillary RCC (CCPAP), 5 angiomyolipoma (AML), 1 medullary RCC (MRCC), 1 mucinous tubular and spindle cell carcinoma (MTSCC), 1 RCC unclassified (RCC-U), 1 PRCC/MTSCC, 15 urothelial carcinoma and 35 others (including metastasis, and lymphoma etc). Overall, 88% of in vivo NCB cases yielded adequate material. 30 patients underwent subsequent nephrectomy. The biopsy diagnosis was confirmed on nephrectomy in 29 of 30 cases, with a concordance rate of 96% (24/25) in CCRCC, 100% (2/2) in CHR-RCC, 100% (2/2) in oncocytoma and 100% (1/1) in MTSCC. There was a significant difference in clinical management (ablation, surgery, chemotherapy, vs active surveillance [AS]) between each diagnostic group (table 1). Of the 80 CCRCC cases, 84% were treated and 16% went on AS. Of the 44 benign or LG cases, 35% were treated and 65% went on AS.

Table 1. Clinical management following biopsy diagnosis.

Diagnosis on biopsy	Total	Cryoablation	Nephrectomy	Chemotherapy	Active Surveillance
Clear cell RCC	80	12	24	31	13
Papillary RCC	7	3	0	2	2
Chromophobe RCC	9	2	2	1	4
Oncocytoma	9	1	2	0	6
Low grade oncocytic renal neoplasm, NOS	9	0	0	0	9
Clear cell papillary RCC	4	1	0	0	3
AML	5	0	0	0	5
Misc*	5	0	2	3	0
Total	128	19	30	37	42

*Includes 1 MRCC, 1 RCC-U, 1 sarcomatoid carcinoma, 1 MTSCC, 1 PRCC/MTSCC


Conclusions: In vivo percutaneous NCB of renal masses yields diagnostic material in 88% of cases with high diagnostic accuracy. This information is useful in deciding subsequent management of these patients.
Category: Genitourinary (including renal tumors)

Tuesday, March 20, 2012 9:00 AM

Platform Session: Section A, Tuesday Morning