也可能是由于出乳口堵塞或者输乳管被皮肤堵塞.They can be caused also by a plugged duct or by skin blocking a milk duct....

“输乳管”的拼音为：shū rǔ guǎn...

“输乳管”的英语可以翻译为：ductus lactiferi，lactiferous duct，galactophore ...