What causes lactation in elderly women who have since passed child bearing?

What causes lactation in elderly women who have since passed child bearing?
go to the doctor for a breast examination.
there are a few possible cause of leakage in the breast: thyroid disease, certain drugs, trauma to the breast, and commonly, a disease known as prolactinoma where a benign growth is present in a gland in the brain. It is not too serious and can be treated with a pill.