Madonna and husband Guy Ritchie have a son, Rocco, 7, and are raising a Malawian boy they want to adopt.
"He's the life of the party," she said of David, who she brought home from Africa in 2006. "He loves music, he's an amazing dancer.... He's a character."
She said caring for David is no different from her raising her biological children: "I thought it was gonna be, but it feels the same to tell you the truth."
As for speculation that her marriage is on the rocks, Madonna said: "It is ridiculous. ... I don't pay much attention to it."
The singer's spokeswoman Liz Rosenberg recently dismissed media reports that the Ritchies have split up, saying they "remain happily married." Rosenberg said that Madonna and filmmaker Ritchie, 39, were "joyfully back together at home in London" after living in separate countries for work purposes.
Madonna, whose new album "Hard Candy" arrives April 29, told "Yo on E!" that she plans to spend the summer in New York, and that she might kick off a tour this fall.