Utility of fine‐needle aspiration and core biopsy with touch preparation in the diagnosis of renal lesions

BACKGROUND: Cytologic evaluation by fine-needle aspiration (FNA) and core biopsy (CB) with touch preparation (TP) is used in the diagnosis of renal lesions. METHODS: Consecutive image-guided FNA and CB, with or without TP, of renal lesions were reviewed. The cytology diagnoses were correlated with the radiology, surgical specimens, and clinical course. RESULTS: A total of 154 procedures (76 FNA, 17 FNA+CB, 46 CB+TP, 15 FNA+CB+TP) were performed for lesions with benign (21), malignant (123), or indeterminate (10) radiology. Specimen adequacy was satisfactory in 86% of FNAs (93 of 108), 95% of TPs (58 of 61), and 94% of CBs (73 of 78), and is statistically significant for CB with or without TP versus FNA (P = .045). In the subset with concerning radiology (n = 133), specimen adequacy was satisfactory in 83% of FNAs (72 of 87), 95% of TPs (58 of 61), and 94% of CBs (73 of 78) (P = .006 for CB ± TP versus FNA), and procedures were diagnostic in 79% of FNAs (69 of 87), 90% of 61 TPs (55 of 61) and 90% of CBs (70 of 78) (P = .02 for CB ± TP versus FNA). Renal cell carcinoma subtype was reported in 63% of FNA (19 of 30) versus 88% of CB ± TP (43 of 49) (P = .01), and Fuhrman nuclear grade was reported only on CB. The cytology diagnoses correlated with surgical specimens in 94% (33 of 35). The most common treatment was ablation of small (3.0 ± 1.3 cm) masses (n = 47). CONCLUSIONS: Compared with FNA, CB and TP have higher adequacy and diagnostic yield and provide more diagnostic information. Cytology diagnoses are highly accurate when correlated to surgical specimens.