Contrast enhanced ultrasound of renal masses

Table 2 Frequency of benign lesions in consecutive patients

Author	n	Benign	Angiomyolipomas	Oncocytomas	Metanephric adenomas	Atypical cysts	Others	Population
[103]	396	5%			1%7		2%8	Surgery
[104]	30	17%	13%			3%		Ultrasound
[105]	70	26%	1%	4%		14%	7%3	Biopsy
[106]	40	23%	10%			13%		Ultrasound
[107]	35	17%	3%			10%	3%1	Surgery
[108]	173	14%	4%	8%		2%		Surgery
[109]	20	35%	5%	5%			25%2	Surgery
[110]	78	21%	3%	17%				Biopsy
[111]	26	21%	8%	12%				Biopsy
[60]	26	31%	27%		4%			Ultrasound
[80]	29	10%	3%	7%				Ultrasound
[61]	23	34%	30%		4%			Ultrasound
[112]	54	21%	4%	11%		6%		Biopsy
[113]	97	25%	25%					Ultrasound
[4]	30	10%		10%				Ultrasound
[114]	99	7%	1%	6%				Surgery/Biopsy
[115]	543	15%	5%	6%	0.2%		3%4	Surgery
[73]	31	13%		10%			3%5	Surgery
[59]	100	20%	3%	13%	2%		2%6	Biopsy
[64]	954	7%		7%				Surgery
[100]	2770	13%						Surgery
[78]	18	33%	11%			22%		Ultrasound
Own data (unpublished)	143	15%	3%	1%	1%	1%	8%9	Ultrasound

Data are given as percentage; N indicates the total number of included patients.

¹Leiomyoma;

²1 abscess, 1 lesion associated with xanthogranulomatous pyelonephritis, 2 cysts, 1 arteriovenous fistula;

³1 lesion associated with xanthogranulomatous pyelonephritis, 3 lesions associated with chronic pyelonephritis, 1 lesion associated with tuberculosis;

⁴Leiomyoma 0.9%, papillary adenoma 0.6%, abscess 0.4%, haematoma 0.4%, giant cell fibroblastoma 0.2%, lipoma 0.2%, haemangioma 0.2%;

⁵Benign lymphoid infiltrate;

⁶Mixed epithelial and stromal tumor;

⁷Adenoma, not further specified;

⁸Haemangioma 1%, cystic nephroma 0.5%;

⁹Abscess 2%, pseudotumour 4%,focal cystic dysplasia 1%, necrosis 1%.