The NBA announced Saturday on behalf of the Hall of Fame center that he is undergoing treatment for a brain tumor.
The NBA said in a statement that Mutombo is starting treatment in Atlanta and is in great spirits.
"Dikembe and his family are requesting privacy so they can focus on his care," the league said. Good wishes and prayers are what they are thankful for.
After playing 18 NBA seasons for the Denver Nuggets, Atlanta Hawks, Philadelphia 76ers, New Jersey Nets, New York Knicks, and Houston Rockets, he retired.
He played in eight All-Star Games and was the league's top defensive player four times. Hakeem Olajuwon had 3,830 career blocks, more than any other player. The gesture that became his signature was the wag of his right index finger.
In addition to his playing career, Mutombo has been involved in charity work. The Basketball Africa League finished its second season in May and he has served as an ambassador for the sport.
The basketball player was in the Hall of Fame. He had been to Springfield, Massachusetts, as well as a pair of preseason games in Saitama, Japan. The U.S. Secretary of State, Antony Blinken, was in the Democratic Republic of the Congo in August to attend an event with the basketball legend.
"You've done a lot to bring the world together, you've done it well," said Blinken when they were together.
The Dikembe Mutombo Foundation was established in 1997 to improve health, education and quality of life for the people in the Democratic Republic of the Congo. A 170-bed hospital in the capital city of the Democratic Republic of the Congo was built by his foundation and has treated half a million people.
He has served on the boards of many organizations.
The AP contributed.