Former NFL quarterback Alex Smith announced his daughter Sloane, who is the youngest of three children he has with his wife, Elizabeth Barry, underwent an emergency craniotomy to remove a malignant brain tumor.

He announced on Instagram on Saturday that Sloane was taken to the emergency room on May 10 with "stroke-like symptoms" before an MRI revealed "a large brain tumor."

The procedure lasted 10 hours, which Smith called "the most excruciating time of our lives," but the neurosurgeons at Stanford Children's removed 100 percent of the tumor.

"Sloane—in her true form—bounced back from brain surgery like a rockstar! She didn't skip a beat," he wrote. "After weeks of waiting on pathology, we learned that Sloane's tumor is a very rare malignant tumor with very few documented cases—without a clear road map for treatment. We are currently awaiting more tests and gathering as many opinions as we can from doctors across the country to decide the best path forward. We wish this were easy, clear-cut and someone gave us a how-to guide. It's anything but that."

Smith said Sloane has recovered from surgery and is "back to her bubbly self. Singing, dancing, laughing and feeling good."

Addressing the family's loved ones, he wrote, "We know it’s not over and we have a journey ahead of us, but without all of you we could not have gotten this far. We are sorry if we seem withdrawn. It’s because we are… We have been inundated with doctors appointments, scans, labs and trying our best to navigate through this. Most importantly, we’re healing together as a family."

Smith played for the San Francisco 49ers, Kansas City Chiefs and Washington during a 16-year NFL career that started when he was selected first overall in the 2005 draft by the 49ers.

He retired in April 2021 after completing a miraculous comeback from a devastating leg injury suffered in 2018. During a game against the Houston Texans in November of that year, Smith suffered spiral and compound fractures in his right leg while being tackled.

Smith underwent 17 surgeries spread out across four hospital stays after developing an infection. Doctors discussed amputating the leg at one point.

Following a return to the field in 2020 that saw him play in eight games and start six, compiling a a 5-1 record as a starter, Smith was named the NFL's Comeback Player of the Year.