Accuracy scores per attribute by institution in the three settings: convolutional neural network (CNN) in only one institution (CNN1) trained on only Massachusetts General Hospital (MGH); CNN in only two institutions (CNN2) trained on MGH and Brigham and Women’s Hospital (BWH); and CNN in only four institutions (CNN4) trained on MGH, BWH, Liaquat National Hospital & Medical College (LNH), and North Shore Medical Center (NSMC). (*) LNH and NSMC do not appear because all of their reports were used for training. ADH, atypical ductal hyperplasia; ALH, atypical lobular hyperplasia; DCIS, ductal carcinoma in situ; FH, Brigham and Women’s Faulkner Hospital; HFH, Henry Ford Hospital; IDC, invasive ductal carcinoma; ILC, invasive lobular carcinoma; LCIS, lobular carcinoma in situ; NWH, Newton-Wellesley Hospital.