Table 2.

Characteristics of the cohort of 240 cases used in the observer evaluation, including the pathological and morphological characteristics of the lesions.

Cases	240
Mean age in years (range)	56 (30–81)
Median compressed breast thickness in mm (range)	59 (27–99)
BI-RADS breast density	A: 27/240 (11%) B: 93/240 (39%) C: 105/240 (44%) D: 15/240 (6%)
Median size in mm of malignant lesions (range)	15 (3–116)
Morphology of the key findings of malignant breasts	Mass: 40/71 (56%) Calcifications: 17/71 (24%) Mass + calcifications: 2/71 (3%) Architectural distortion: 8/71 (11%) Mass + architectural distortion: 1/71 (1%) Asymmetric density: 3/71 (4%)
Morphology of the key findings of benign breasts	Mass: 26/75 (35%) Calcifications: 38/75 (51%) Mass + calcifications: 2/75 (3%) Architectural distortion: 4/75 (5%) Asymmetric density: 4/75 (5%) Mass + asymmetric density: 1/75 (1%)
Histology of malignant breasts	IDC (invasive ductal ca.): 32/71 (45%) ILC (invasive lobular ca.): 7/71 (10%) DCIS (ductal ca. in situ): 15/71 (21%) IDC + DCIS: 11/71 (15%) IDC + other invasive type: 4/71 (6%) Invasive papilloma: 1/71 (1%) Invasive medullar ca.: 1/71 (1%)
Histology of benign breasts	Atypical ductal hyperplasia: 22/75 (29%) Fibroadenoma: 12/75 (16%) Adenosis: 6/75 (8%) Fibrocystic changes: 5/75 (7%) Breast cysts: 4/75 (5%) Fat necrosis: 3/75 (4%) Papilloma: 3/75 (4%) Apocrine metaplasia: 2/75 (3%) Others: 18/75 (24%)