Bacteriology of mammary duct ectasia

The role of infecting organisms in initiating or complicating mammary duct ectasia and its related change of periductal mastitis remains uncertain. Some believe that mammary duct ectasia is a natural phenomenon of the ageing breast and this is supported by reports of occult duct ectasia in 25-75 per cent of breasts examined at post mortem in women in whom there has been no previous breast disorder. Others suggest that ductal dilatation occurs as a consequence of episodes of infection within the breast leading to destruction of elastica in the duct wall. Evidence for this view is the recent finding that, contrary to previous reports, organisms, particularly anaerobes, can be identified in the nipple discharges as well as purulent exudates (e.g. from mammillary fistulae) which can be associated with this condition.