Indianapolis Colts head coach Chuck Pagano was diagnosed with leukemia, according to NFL Network’s Albert Breer.

ESPN’s Chris Mortensen stated Pagano’s case treatable. However, he is expected to be hospitalized for four to six weeks while dealing with the disease.

Bob Kravitz of The Indianapolis Star offered an explanation of Pagano’s diagnosis:

 The illness is acute promyelocytic leukemia. According to the American Cancer Society website, “early diagnosis and treatment of acute promyelocytic leukemia (APL) … is important because patients with APL may develop serious blood-clotting or bleeding problems. … Treatment induces remission in 80 to 90 percent of patients.”

Offensive coordinator Bruce Arians is expected to take over as interim head coach.

The 52-year-old Pagano is expected to miss several games including this Sunday’s meeting with the Green Bay Packers.