Table 1. Cohort demographics and radiologic/pathologic features.

Tumor features	sRCC(n=17)	ccRCC(n=17)	P
Mean age (years)	60.3	64.5	0.413
Sex (males)	10	10	1
Median tumor size by pathology (cm)	11	9	0.493
Median tumor size by MRI (cm)	9.8	9	0.731
Pathologic tumor category			0.21
T1 and T2	3	7
T3	13	8
T4	1	2
Pathologic N category			0.023*
N0	7	5
N1	5	1
N2	2	0
NX	3	11
Clinical metastasis			1
Negative (M0) or unknown	9	9
Positive (M1)	8	8
Perineural invasion	2	0	0.145
Lympho-vascular invasion	10	6	0.169
Renal capsule invasion	13	8	0.078
Tumor necrosis			0.008*
0%	0	8
1–20%	10	4
21–40%	5	4
41–60%	2	0
>60%	0	1

*, significant difference. RCC, renal cell carcinoma; MRI, magnetic resonance imaging; ccRCC, clear cell renal cell carcinoma.