表 1. The ultrasonic classification and malignancy proportion of the NMLs cases.

NMLs 病例超声分型及恶性占比

Type	Total (n=407)	Malignance (n=187)	Benignity (n=220)	Malignancy proportion
Ⅰa	99	25	74	25.3%
Ⅰb	96	79	17	82.3%
Ⅱa	107	24	83	22.4%
Ⅱb	54	42	12	77.8%
Ⅲ	18	8	10	44.4%
Ⅳ	17	2	15	11.8%
Ⅴ	16	7	9	43.8%