Mammary duct ectasia is a benign breast disease that can mimic invasive carcinoma clinically. The process that causes the mammary duct ectasia is still being debated but histologically it is characterised by dilation of major ducts in the subareolar region. The breast ducts contain eosinophilic granular secretions and foamy histiocytes. The secretions may undergo calcification and this may be the presenting sign1 .
This is a companion discussion topic for the original article at https://patient.info/doctor/mammary-duct-ectasia-and-periductal-mastitis