Clinicopathological characteristics and typing of multilocular cystic renal neoplasm of low malignant potential

Table 1 General information of patients

Medical data1	Renal cyst	Cyst combined with renal tumor	P value
Age (continuous)			0.35
Mean (IQR)	62 (50–72)	59 (51–68)
Sex (No. of cases)			0.72
Male, n (%)	675 (57.94)	180 (50.70)
Side (No. of cases)			0.16
Left, n (%)	561 (48.15)	165 (46.48)
Cyst diameter (cm)			0.27
Mean (IQR)	12 (9–14)	7 (6–9)
Operation method (No. of cases), n (%)			< 0.001
Renal cyst topping decompression	1165 (100.0)	346 (97.46)
Radical nephrectomy	0	3 (0.85)
Nephron sparing surgery	0	6 (1.69)
Pathological type (No. of cases), n (%)			< 0.001
Renal cyst	1132 (97.18)	312 (87.89)
MCRNLMP	33 (2.82)	43 (12.11)
Fuhrman grade (No. of cases), n (%)			0.06
I	13 (39.39)	26 (60.47)
II	20 (60.61)	17 (39.53)

¹Continuous variables were compared by independent samples t-test.

IQR: Interquartile range; MCRNLMP: Multilocular cystic renal neoplasm of low malignant potential.

Table 2 Comparison of postoperative pathological positive rates between simple renal cysts and cysts combined with renal tumors diagnosed preoperatively, n (%)

Index1	Group	Benign	MCRNLMP	P value
Preoperative diagnosis	Simple renal cyst (type I)	735 (98.52)	11 (1.48)	< 0.001
	Complex renal cyst (type II)	397 (94.74)	22 (5.26)
	Cysts combined with renal tumors (type III)	312 (87.89)	43 (12.11)

¹The above results with χ² test showed significant difference in the pathological positive rate of various preoperative diagnosis (P < 0.001).

MCRNLMP: Multilocular cystic renal neoplasm of low malignant potential.

Table 3 Univariate cox regression analysis of positive rates in patients with multilocular cystic renal neoplasm of low malignant potential

Univariate analysis	Odds ratio	95%CI	P value
Preoperative diagnosis			< 0.001
Simple renal cyst (type I)	1 (reference)
Complex renal cyst (type II)	3.67	2.57–5.13
Cysts combined with renal tumors (type III)	9.19	6.46–12.88
Growth rates			< 0.001
< 2.0 cm/yr	1 (reference)
≥ 2.0 cm/yr	43.51	30.90-61.66

Table 4 Comparison of postoperative pathological positive rates in various growth rates during preoperative monitoring, n (%)

Index1	Group	Benign	MCRNLMP	P value
Growth rates	≥ 2.0 cm/yr	236 (77.63)	68 (22.37)	< 0.001
	< 2.0 cm/yr	1208 (99.34)	8 (0.66)

¹The above results of χ² test showed the significant difference in the pathological positive rate of various growth rates (P < 0.001).

MCRNLMP: Multilocular cystic renal neoplasm of low malignant potential.

Table 5 Comparison of differences in the positive recurrence rate of various treatments, n (%)

Index1	Group	Renal cyst topping decompression + active monitoring	Renal cyst topping decompression + nephron-sparing surgery or radical nephrectomy	P value
Re-examination	No recurrence or metastasis	66 (98.50)	9 (100.0)	1
	Recurrence or metastasis	1 (1.50)	0 (0.00)

¹The above statistical results of the Fisher’s probability test showed that the positive rate of recurrence after various surgical methods was not significant (P = 1).

Table 6 Comparison of differences in the positive recurrence rate of various surgical methods, n (%)

Index1	Group	Renal cyst topping decompression + nephron-sparing surgery	Renal cyst topping decompression + radical nephrectomy	P value
Re-examination	No recurrence or metastasis	6 (100.0)	3 (100.0)	1
	Recurrence or metastasis	0	0

¹The above statistical results of the Fisher’s probability test showed that the positive rate of recurrence after various surgical methods was not significant (P = 1).