Expert answer:
Nodules or lumps in the breast can be benign or malignant. Particularly during breastfeeding, they may be the result of dairy cysts (bags full of milk) and infections (mastitis), which are conditions benign, but which require gynecologist evaluation and treatment on certain occasions.
Other causes of breast nodules include: benign fibrocystic changes, fibroadenomas, cysts, and breast cancer. Only after the evaluation of the gynecologist and, if necessary, mammography and breast ultrasonography, the cause of the nodule can be diagnosed, and the appropriate treatment instituted.
