Mastocytosis is a condition in which the nipples do not express milk. Mastocytosis, also known as lobular hyperplasia or cystic hyperplasia, is caused by an imbalance in the levels of estrogen, progesterone and lactogen, and its typical clinical manifestation is the onset of the menstrual cycle, with pain and swelling of the breast and even the formation of lumps. As the underlying cause of mastocytosis is lobular hyperplasia caused by imbalance of hormone levels, it is not connected to the milk ducts, so it does not lead to milk secretion through the milk ducts and out of the body, so patients with mastocytosis do not have milk overflow from the nipples.