Good news for Melania Trump ... she's recovering "really well" after undergoing kidney surgery on Monday ... this according to her husband, Donald Trump.
Melania underwent an embolization procedure at Walter Reed National Military Medical Center near Washington D.C. to treat a benign kidney condition, according to the White House.
The White House did not say exactly why Melania needed the procedure -- but medical experts say it's minimally invasive.
"Our great First Lady is doing really well," Trump tweeted early Tuesday morning ... "Will be leaving hospital in 2 or 3 days."
He added, "Thank you for so much love and support!"