"When I hear benign kidney condition, most of the time, you're thinking a cyst and a cyst is basically a fluid-filled structure that can sometimes develop on top of the kidney, or within the kidney", Gupta said.
He says "she is in good spirits", and adds, "Thank you to all of the well-wishers!"
Melania's not the only first lady to undergo surgery, but a hospitalization this long hasn't occurred for a first lady since Nancy Reagan back in 1987.
"Heading over to Walter Reed Medical Center to see our great First Lady, Melania", Trump tweeted.
SCOTUS ruling paves the way for sports betting in NY
And if politicians believe they can get their hands into the lucrative bookmaking cookie jar, you can bet they will act quickly. Proponents say Iowa missed the boat by not passing a law allowing casinos to offer sports wagering before the U.S.
The treatment of choice for the condition is through embolization, which involves cutting off the blood supply to the abnormal growth so it would shrink and eventually die off.
"The potential problems from these benign tumors if they get big enough - (are) pain, bleeding, blood in the urine", Rogers said. Dr. Craig Rogers, the head of Henry Ford Hospital's Renal Surgery said she likely had some painful symptoms. This is done by placing blocking agents in a blood vessel - think gelfoarm, metallic coils or PVA granules.
The White House says the 48-year-old first lady had the procedure Monday morning.
But once the East Wing announced her hospital stay, the President boarded Marine One two hours later to visit his wife.
The Slovenia-born wife of Donald Trump underwent an embolisation procedure, said her communications director Stephanie Grisham. She is expected to remain hospitalized for the rest of the week.
Last week, Mrs. Trump unveiled her "Be Best" campaign focused on bullying, social media, opioid abuse and other challenges facing American children. Grisham, who has visited the first lady, later told CBS that the first lady is "doing very well" and is in "good spirits".