Christmas came in October for Casimer Joseph "CJ" Banaszek IV, when his third bone marrow transplant finally proved successful. The brave 13-year-old Petaluman isn't out of the woods yet, but his family is optimistic his two-year battle with Chronic Myelogenus Leukemia is nearing its end.

"I think the big picture is very good and uplifting and hopeful," said his mom, Heather Banaszek, on Dec. 20. "He won't be home for Christmas, but that's fine. We'll do Christmas next year."

CJ hasn't been home since July 8, when he was admitted to the Benioff Children's Hospital at the University of California, San Francisco to undergo his second bone marrow transplant.

Leukemia is a cancer of the bone marrow, and a transplant is needed to replace the infected marrow with cells from a healthy matching donor, thus ridding the body of cancer. In some cases, the body rejects the donor cells, which happened after CJ's first bone marrow transplant in 2012 — and ultimately, his second transplant in July.

"All of the sudden it just wasn't there, all of that (donor) bone marrow just disappeared," Heather said.

But, as doctors searched CJ's cells, they found residue from the first donor's marrow, a sign the procedure wasn't a complete failure. Doctors reached out to the original donor, a man in Germany, who agreed to donate more bone marrow for CJ. On Oct. 11, one week before his 13th birthday, CJ again had his body pumped with healthy cells. So far, his body has not rejected this transplant.

"There's no leukemia they can see," Heather said hopefully, adding that the family is cautiously optimistic. "We don't make a big deal out of it and say he's cancer-free after all we've been through."

CJ has remained in isolation at the hospital because his severely weakened immune system makes him highly susceptible to any infection. He was supposed to be discharged Dec. 2, but he developed a severe infection that required emergency surgery, setting back his recovery by weeks.

"He needs more time to heal," Heather said. "He's really quite amazing, he just handles it."

She said while her son remains in isolation, he isn't alone. His mother or father spends every night with him, and he is surrounded by faces of the many people who love him.

"We decorated his room with all these photos," Heather said. "He literally has dozens of people smiling at him every day."

Back home in Petaluma, skeletons and zombies await CJ's return. Since Halloween is his favorite holiday, his parents have refused to take down the decorations until after CJ gets home to enjoy them.

"I tried to make it more festive by putting Santa hats on the skeletons," Heather laughed.

This Christmas, CJ, his parents and older sister planned to spend the day together in the hospital, opening presents, sharing a meal and watching Christmas movies.

"It's not how we would have liked to spend Christmas, but we're just happy he's with us," Heather said. "After our time in the hospital, we've seen a lot of people who haven't made it and we know we're lucky to have him."

Heather said the family is also lucky for the support they've received back home. The young man who loves video games, Legos and "Star Wars" has captured the hearts of many in Petaluma — with hundreds of people donating money to cover medical expenses, or joining the national Bone Marrow Registry on CJ's behalf.

"That support has really gotten us through some difficult times," Heather said. "We do break down sometimes, you have to. You have to go through it, not around it. But that support helps build us back up."

(Contact Emily Charrier at emily.charrier@arguscourier.com)