By Stephanie Stahl

PHILADELPHIA (CBS) — Doctors and staff at Hahnemann University Hospital set up a special blood drive Friday for a beloved colleague, a doctor recently diagnosed with cancer. But this isn’t about supporting just one person. The group at Hahnemann said the blood drive will help everyone.

Dr. Andres Castellanos is usually in the operating room at Hahnemann. But now the surgeon is suddenly a cancer patient getting immunotherapy. Dr. Castellanos was diagnosed with leukemia two weeks ago.

“It was a little bit shocking at the beginning,” Dr. Castellanos said, “because you’re 50, you’re in good health, you work in a hospital. You’re supposed to be the picture of health.”

That is, until he noticed some bruising and swelling and he felt tired.

What is it like being a doctor who is now a patient?

“It’s actually a humbling experience,” he said. “I think that in the future if anything it’s probably going to make me a better physician, help me connect with my patients a little bit more.”

Friend and colleague Dr. David Stein says the surgery department was stunned when Dr. Castellanos was diagnosed.

“This is probably one of the most devastating pieces of news I’ve ever heard,” Dr. Stein said. “When you get this devastating news, how do you act? What do you do? And we all felt the need to do something.”

They turned shock into action, quickly organizing Friday’s blood drive. It’s “not just to serve Andres and Hahnemann, but the entire Red Cross and all the needs throughout Philadelphia,” Dr. Stein said.

The blood collected will go to the Red Cross and be available to everyone and Dr. Castellanos as he needs it for transfusions.

People all over the hospital were eager to donate and show their support.

“I think it’s nice to know you have so many people that care about you,” Dr. Castellanos said.

His wife and 8-year-old son keep him company and entertained during his weekly infusions, joking that Mom’s the better driver, but Dad’s the better surgeon.

Dr. Castellanos hopes to be back doing surgery as soon as he can. Following this 12-week round of immunotherapy, he’ll need a bone marrow transplant. They’re starting to look for suitable donors.

To join the national bone marrow registry, contact Be The Match at https://bethematch.org/support-the-cause/donate-bone-marrow/join-the-marrow-registry/

To reach the American Red Cross, you can go to http://www.redcross.org/local/pennsylvania/eastern-pennsylvania

Stephanie Stahl