Brooklyn Teacher's Battle With Brain Cancer Rallies Support

BOERUM HILL, NY — A brain tumor didn't stop Charl Castelyn from showing up for his sixth-grade students in Brooklyn this September. But then two weeks ago, everything changed.

Castelyn's tumor has grown over the last year despite aggressive surgeries, radiation and chemotherapy. And over the last two weeks, he has rapidly lost short-term memory.

"It's just been such a drastic change in just a couple weeks," Castelyn's husband, Craig Strulovitz, told Patch.

After 19 years of teaching math in New York City, Castelyn's community is now pitching in to help the dedicated teacher return to his adventurous self. The $32,347 donated in just four days will help Castelyn get the 24-hour care he needs during treatment, including speech and physical therapy and home health aid.

"The fast support that this has gotten is because he is such a special and amazing man, human, teacher," said Castelyn's long-time friend and coworker Katherine Schrup. "I am constantly brought to happy and overwhelmed tears by the generosity of folks."

Castelyn first battled a rare type of cancer in his salivary gland in 2012. In 2018 during a follow-up scan, doctors found another mass they had missed years before — on Castelyn's brain.

In 2022, Castelyn's cancer started spreading despite treatment. But until about two weeks ago, Castelyn was able to continue his normal, active life.

Castelyn started off this school year co-teaching sixth-grade math with Schrup, but his condition deteriorated too quickly to continue. Just a couple of weeks was plenty for Castelyn to make his mark on the middle school students.

"Just this week, when I told our students that Mr. Castelyn was sick and wouldn’t be returning for a while, they came up with all sorts of ideas to help support him," Schrup said on the GoFundMe.

"It’s a true testament to the impact that Charl has had on so many people. Over the last 19 years of teaching, he has touched the lives of hundreds of students."

Castelyn is a passionate math teacher, driven by the moments he can change a kid's mind about a difficult subject, Schrup said. He started teaching in the Bronx with Teach for America after college and landed at MS 447 shortly after.

Strulovitz can remember many parents saying Castelyn changed the way their children thought about math.

"He's a super dedicated teacher, he loves his job, he loves the kids, and he loves math," Schrup said.

Outside the classroom, Castelyn is social, adventurous, and endlessly curious, Strulovitz said.

"He's curious about a lot of things and not afraid of a lot of things," Strulovitz said.

Schrup said the school community is tight-knit and has made "awe-inspiring" efforts to support Castelyn.

"While Brooklyn has always rallied around Charl during ongoing health issues, this time we are extremely grateful for everyone's support and the donations he has received so far," Strulovitz said.