Lil' Kim was a surprise guest at the annual Hot 97 Summer James concert at the Met Life Stadium in New Jersey - but what really surprised fans was her face.

According to The Inquisitr, the 38-year-old rapper was so unrecognizable that event organizers had to confirm it was actually Lil' Kim performing on the stage and not an impersonator.

Lil' Kim, whose real name is Kimberly Denise Jones, had a lighter complexion and a pinched expression that many suggested was the result of plastic surgery.

Lil' Kim's new look has been under media scrutiny since March, when fans first noticed she looked very different from the rapper they knew from the '90s.

"Her face appears contoured and has a waxy sheen .... It appears that she's undergone injection of fillers as well," celebrity plastic surgeon Dr. Anthony Youn said earlier this year, the Inquisitr reports.

Some believe she has gotten a nose job, botox injections, and has had her skin lightened.

But Lil' Kim's reps have already come out to debunk the rumors, saying that such suggestions are "fictitious, malicious and despicable."

Her rep, C.J. Carter, continued: "We would like to inform fans, the media, and the general public that this is nothing more than the blog site doing its best to conjure up much needed publicity and what better way to do so, than to take an American music icon and create a fictitious platform in which to disrespect and humiliate. We at Team Lil Kim are not taking this lying down and are taking this matter very seriously," E! Online reports.

Lil' Kim wore lace-up black heels, red hot pants, and a black corset top with gold chains and buckles during her short performance at the concert.