Recurrent Nipple Duct Obstruction in Two Breastfeeding Patients: A Case Report and Discussion of the Underlying Pathophysiology.

Nipple pain is a common reason for premature breastfeeding cessation. There exists anecdotal evidence that one cause of lactational nipple pain is a ductal obstruction, but there is no published literature describing this phenomenon. Herein we present two case reports for two patients who experienced breast and nipple pain concurrent with milk flow reduction. Both patients removed a small stone-like obstructing object from their nipple; this action was painful for one of the patients, resulting in immediate release of milk and relief from breast pain. Both patients experienced recurrence of stone formation in their nipple ducts. We analyzed the mineral composition of the obstructing objects and breast milk using inductively coupled mass spectroscopy. We use literature on teat obstructions in dairy cows and dacryolith and sialolith formation to propose hypotheses as to how the formation of obstructing objects in milk ducts might occur. Future research directions for determining the pathophysiology, clinical presentation, and management of human nipple duct obstructions are discussed.