Breast Imaging in Pregnancy and Lactation.

All breast disorders found during pregnancy and lactation should be carefully evaluated. Most of them are benign, but it is essential to exclude pregnancy-associated breast cancer (PABC), which is too often diagnosed late. The first-line imaging technique is ultrasound (US), which must be completed by mammography if there is any clinical or US suspicious sign. In lactating patients with PABC, breast magnetic resonance imaging (MRI) can be useful for local assessment. Management depends on the precise analysis and BI-RADS1 classification of the lesion. During pregnancy and lactation, there is an overlap in imaging: many benign lesions can grow, infarct, become heterogeneous and thus suspicious, and on the other hand, PABC does not always present with typical malignant features. That is why biopsy must be performed if after the clinical and radiological evaluation the doubt persists, i.e. for all BI-RADS 4 and 5 lesions, and for some BI-RADS 3 lesions.