They are also called Cysts of Moll or sudoriferous cysts.
2.
Also just saw that the article sudoriferous gland states that "'sweat is a secretion " '.
3.
The breast is in effect " a greatly modified collection of sudoriferous glands " and its structures are also formed before birth.
4.
According to my copy of " Gray's Anatomy " ( the 1958 edition, but I don't imagine this has changed ), sweat ( sudoriferous ) glands are formed in the fetus during the 4th month of pregnancy.