Nipple inversion occurs due to involvement of
Cooper ligament
Subareolar duct
Parenchyma of breast
Subdermal lymphatics
Mastitis in many cases the lactiferous ducts will first become blocked by epithelial debris leading to stasis; this theory is suppoed by the relatively high incidence of mastitis in women with a retracted nipple.Periductal fibrosis is a sequela of periductal mastitis and may result in nipple retraction.Schwaz surgery 15th edition pg: 509
Endocrinology and breast