CHICAGO (CBS) — Doctors have discovered cancerous cells in Cardinal George’s kidney, the archdiocese announced on Friday.

The cardinal underwent a procedure on Wednesday at Loyola University Medical Center.

Friday, he met with his doctors who reviewed with him test results which showed there were cancerous cells in the kidney and in a nodule, which was removed from the liver.

In a statement, the archdiocese said doctors will work with the cardinal to plan a course of treatment.

“The Cardinal will be resting at home this weekend and will be on retreat next week,” the statement said.

Cardinal George, 75, was diagnosed with bladder cancer in 2006 and underwent surgery in August of that year.

Dr. Dennis Pessis of Rush Medical College University speculates the latest cancer could have come from the earlier bout.

“It’s very likely this is a metastatic lesion from the bladder,” he said.

George, whose retirement had been imminent, has long been stoic about his lifelong health issues. He contracted polio at the age of 13.

Parishioners at Holy Name Cathedral expressed shock at the news Friday, CBS 2’s Brad Edwards reports.

“I guess God has another plan for him, a different plan, so I’m very sorry to hear that and I surely will be praying for him,” Andrea Quinn said.