12/14/2011 11:05 am ET | Updated Dec 14, 2011

Miley Cyrus Blasts Breast Implant Rumors (PHOTOS)

Can't a girl show a little cleavage without having to respond to breast implant rumors the next day?

Not if you are Miley Cyrus. The 19-year-old singer and actress showed up to the CNN Heroes red carpet on Sunday night wearing a very low-cut yellow gown.

With her boyfriend Liam Hemsworth on her arm, Miley looked nothing less than gorgeous, but her cleavage baring moment sparked rumors she'd gone under the knife.

On Tuesday, Miley responded to rumors on Twitter:

Cyrus quickly responded again to the fan's twitter account decrying, "And I'm 19!!! BOOBS GROW PEOPLE!"

The rumors were started by RadarOnline, who wrote that Cyrus likely had implants based on the opinions of cosmetic surgeons who had never treated the singer.

Miley has been quite vocal on Twitter in the last few months, using the microblogging site to scold fans for rude messages sent to pal Kelly Osbourne, defend herself and Demi Lovato from those calling them fat, and she spoke out against clothing retailer Urban Outfitters for donating more than $13,000 to the former Pennsylvania senator -- and famously anti-gay -- Rick Santorum's political action committee.

Miley has definitely grown up:

Miley Cyrus