The stunning news, first reported by Bob Kravitz of the Indianapolis Star, comes after Pagano reportedly felt unusual fatigue in recent weeks, and then went to get blood tests during the Colts' bye week. NFL.com and NFL Network's Albert Breer confirmed with Pagano that he has a treatable form of leukemia.
"Will be back REAL soon," Pagano wrote to Breer via email.
Pagano said doctors told him he would be hospitalized for four to six weeks, but he told Breer he's shooting for four weeks.
Dr. Larry Cripe of the IU Simon Cancer Center announced during a Monday news conference that Pagano has acute promyelocytic leukemia, which an Oncology/Hematology expert told NFL.com and NFL Network's Ian Rapoport relatively is easy to treat compared to other forms of acute leukemia and that it is potentially curable.
"The goal of the treatment is to cure the disease," Cripe said. "The process is long and complicated, and we're just starting right now. For the next several weeks this will be day by day."
Cripe declined to discuss the success rate for remission in cases involving this type of leukemia.
"There's no doubt that for the next several weeks, day by day, he's at a risk for complications," Cripe said.
Colts owner Jim Irsay said of Pagano: "I know he is just ready to take this fight on, and he's a fighter."
"I'm very optimistic that he will beat this thing," Irsay said. "Probably not in the cards that he will be able to be all in this season."
Offensive coordinator Bruce Arians will take over as interim coach.Follow Gregg Rosenthal on Twitter @greggrosenthal.