Table 1. Distributions of histopathological characteristics of breast lesions for both groups.

	Training group		Testing group
	Number	Percentage	Number	Percentage
Malignant lesions	323	32.3	107	52.5
Invasive ductal carcinoma	222	22.2	86	42.2
Introductal carcinoma	8	0.8	2	0.9
Ductal carcinoma in situ	85	8.5	18	8.8
Mucinous carcinoma	4	0.4	0	0
Others	4	0.4	1	0.5
Benign lesions	677	67.7	97	47.6
Fibroadenoma	71	7.1	11	5.3
Fibrocystic changes	491	49.1	58	28.4
Intraductal papilloma	11	1.1	2	0.9
Hyperplasia	6	0.6	2	0.9
Phyllodes tumor	8	0.8	0	0
Inflammation	2	0.2	1	0.5
Follow-up	88	8.8	23	11.3
Microcalcifications only	623	62.3	110	53.9
Masses only	221	22.1	35	17.2
Microcalcifications and masses	156	15.6	59	28.9

Note—The follow-up period was at least two years. Only both systematic clinical examination and mammogram showed no malignant findings to the suspicious benign-appearing lesion in this period, can the patient be admitted into the benign group.