Hi,
I didn't find anything by searching the forum : I really like Lenaick from a French artist named Toma.
Lenaick is a character that lives in the 20s in Paris and suffers from virginal hypertrophy (a good excuse to draw big breasts
).
There is not direct breast expansion but he also drew Lenaick at 12 (she's now 15) to see the process.
His Deviantart gallery contains some drawings. I created an archive with all his gallery and even some drawing that are not in it.
Enjoy.
Some examples attached.
The archive :
http://rapidshare.com/files/34963682/Toma.zip