Trump's communications director, Stephanie Grisham, said the first lady had an embolization procedure, which starves the blood supply to the affected area.
"The procedure was successful and there were no complications," Grisham said, adding that Trump would likely remain at the hospital for the rest of the week.
"The first lady looks forward to a full recovery so she can continue her work on behalf of children everywhere."
"Heading over to Walter Reed Medical Center to see our great First Lady, Melania. Successful procedure, she is in good spirits. Thank you to all of the well-wishers!" he wrote on Twitter.