Eighteen-month-old Kristen Hoenshell has a rare and aggressive form of cancer. What began as a tumor behind her eye has led to surgery and 38 weeks of weekly visits to Dana-Farber Cancer Institute, where she receives powerful doses of chemotherapy that leave her weak and occasionally sick.

Yesterday, when she showed up for another round of treatment, she was greeted by something special. As her cousin Megan Souza pointed out the window of a third-floor walkway, ironworkers perched on the sixth floor of a partially constructed building nearby hoisted a massive I-beam into place. It was emblazoned, in bright pink spray paint, with Kristen's name.

"Look out the window," Souza said, as she held Kristen in her arms. "There's your name up there. There's your name, Kristen." The girl, bald from her treatments, smiled shyly.

It has become a beloved ritual at Dana-Farber: Every day, children who come to the clinic write their names on sheets of paper and tape them to the windows of the walkway for ironworkers to see. And, every day, the ironworkers paint the names onto I-beams and hoist them into place as they add floors to the new 14-story Yawkey Center for Cancer Care.

The building's steel skeleton is now a brightly colored, seven-story monument to scores of children receiving treatment at the clinic - Lia, Alex, and Sam; Taylor, Izzy, and Danny. For the young cancer patients, who press their noses to the glass to watch new names added every day, the steel and spray-paint tribute has given them a few moments of joy and a towering symbol of hope.

"It's fabulous," said Kristen's mother, Elizabeth, as she held her daughter and marveled at the rainbow of names. "It's just a simple little act that means so much."

Most days, the walkway fills up like the passageway of an aquarium, packed with children gazing through the glass. When a new name goes up on the building, the children cheer and clap. Yesterday, Juclaubern Palmer Osias, a 16-year-old from Holbrook who was diagnosed with cancer last year, saw his name immortalized in green paint on a beam on the seventh floor.

"It's your name," he said. "It makes you feel important."

It's given a sense of satisfaction to the ironworkers, too.

"Everybody saw the kids smiling," said Mike Walsh, the foreman for the ironworkers, from Local 7, whose wife, Sheila, is a nurse at Dana-Farber. "And that's what you want to do, is keep them smiling, especially if they're going for treatment in there."

The ironworkers made a similar tribute in 1996, when they painted the names of young cancer patients on beams they used to build the Smith Research Laboratories at Dana-Farber. For a time, a short film about the project was shown in movie theaters to raise money for the Jimmy Fund.

This time, the ironworkers knew they wanted to honor the children again. Over the last month, they have painted more than 100 names on the building and emblazoned part of their crane with a likeness of SpongeBob SquarePants. They have also painted a few special messages on the steel, like "Hi Hanna Get Well ASAP :)"

Yesterday, crawling on their stomachs in the bitter cold and whipping winds, the ironworkers looked down at the latest batch of names posted in the walkway window. Looking up at them were Kristen and her sisters, Cathryn, 5, and Hannah, 3, who have been accompanying her to chemotherapy. They pointed as the ironworkers painted the girls' names onto the side of a 4-ton I-beam and hoisted it on to the seventh floor.

"She'll always be a piece of this building, which is a good feeling to have," Elizabeth Hoenshell said, holding Kristen. "They don't have to do this, the guys. They could just do their job and do a good job at it and give us a building that we can get treatment at, but they go the extra step and that's huge."

One day, years from now, Hoenshell said, she hopes to take Kristen back to the clinic, and show her where her name is inscribed. "I'm going to stand her right here at this pedestal and say, 'Look right up,' and 'That was you,' " she said. "Maybe I'll take her over there for a little walk. She can step on her name," she said, laughing.

Michael Levenson can be reached at mlevenson@globe.com.

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