Table 1.

Characteristics of patients divided by the year of 2018

	Before 2018(26)	2018 and later(25)	P
Age(year)	7.0(0.2 ~ 14.0)	9.0(0.3 ~ 14.0)	0.224
Age (≤ 2 years old)	10	4	0.072
Max diameter(cm)	2.0(0.4 ~ 5.4)	1.7(0.7 ~ 3.6)	0.406
Max diameter(≤ 2.0 cm)	14	17	0.301
TSS	7	19	< 0.001
Elevated serum AFP level	3	1	0.610
Unclear boundary in US	4	5	0.726
Clinical diagnosis of malignant tumor	2	3	0.668
FSE	4	14	0.002

TSS testis sparing surgery, US ultrasound examination, FSE frozen-section examination