EUS-guided FNA aspiration of kidney masses: a multicenter U.S. experience.

Background: Tissue sampling of renal lesions is traditionally performed with percutaneous US or CT guidance. To date, only 3 known cases of EUS-guided FNA (EUS-FNA) of a renal mass have been reported.

Objective: To describe a multicenter experience with the indications, yield, and complications from attempted EUS-FNA of a kidney mass.

Design: Retrospective case series.

Setting: Six tertiary referral hospitals in the United States.

Patients: Consecutive subjects undergoing attempted EUS-FNA of a kidney mass. Endosonographers at 15 other teaching hospitals were contacted regarding EUS findings and follow-up of any EUS-guided renal biopsies previously attempted or considered at that institution.

Interventions: EUS-FNA of a kidney mass.

Main Outcome Measurements: Biopsy indications, yield, diagnosis, and complications.

Results: Fifteen procedures in 15 patients (9 men; median age 67 years) were performed at 6 (37%) of 16 hospitals (Indiana University plus 15 other hospitals). Kidney masses (median diameter 32 mm; range 11-60 mm) were located in the upper (n = 12) and lower (n = 3) poles of the left (n = 10) and right (n = 5) kidneys, respectively. Initial mass detection was by previous imaging in 13 (87%) patients or by EUS in 2 (13%) patients. Results of EUS-FNA (median 3 passes; range 2-4 passes) in 13 (87%) procedures were diagnostic of (n = 7) or highly suspicious for (n = 1) renal cell carcinoma (RCC), atypical cells (n = 2), oncocytoma (n = 1), benign cyst (n = 1), and nondiagnostic (n = 1). No complications were encountered. Surgical resection confirmed RCC in 7 patients in whom preoperative EUS-FNA demonstrated RCC (n = 5) or oncocytoma (n = 1) or was not performed (n = 1).

Limitations: Retrospective series, small number of patients.

Conclusions: EUS-FNA of renal masses is rarely performed at the U.S. teaching hospitals surveyed. This technique appears safe and feasible and should be considered when results would affect patient management.