Periductal mastitis and duct ectasia: an update

Periductal mastitis and duct ectasia appear to have different clinical syndromes: they affect different age groups and they appear to have different aetiologies. Smoking and bacteria, particularly anaerobic bacteria, have an aetiological role in periductal mastitis whereas duct ectasia appears to be an involutionary phenomenon, with clinically significant duct ectasia being considered an aberration of normal involution. There is no evidence that periductal mastitis precedes duct ectasia. Periductal mastitis and duct ectasia should therefore be considered as two separate conditions.