COLORADO SPRINGS, Colo. – Dr. Paul Grabb peered into the microscope at Sam Esquibel’s 3-day-old brain, set on removing a tumor that threatened the infant’s life.

What the pediatric neurosurgeon saw made him spring back in shock.

A foot!

As he surgically removed it, Grabb also found other partially formed appendages and what appeared to be ropes of an intestine tucked within the folds.

Sam survived the Oct. 3 brain surgery at Memorial Hospital for Children and is home with his parents and doing well.

But his introduction to the world marks one of the strangest moments in medical history.

“It looked like the breach delivery of a baby,” the pediatric neurosurgeon said last week, “coming out of the brain.”

An exact diagnosis is unknown. The growth might have been a teratoma, a congenital brain tumor composed of foreign tissue such as muscle, hair or teeth. But such tumors typically are not as complex as a foot or hand.

It might have been a case of fetus in fetu, a developmental abnormality in which a fetal twin begins to form within another, but those have most often occurred in the torso and not the brain.

“You show those pictures (of Sam) to the most experienced pediatric neurosurgeons in the world, and they’ve never seen anything like it,” Grabb said.

Tiffnie and Manuel Esquibel had little reason to worry Oct. 1 when they went to the doctor. At 41 weeks, it appeared Tiffnie would need to be induced, but otherwise the pregnancy had gone smoothly.

Then an ultrasound revealed trouble in the baby’s brain, and the delivery was planned immediately after the doctor’s appointment. After four hours of labor at Memorial Hospital North, Sam’s health was failing. Tiffnie underwent an emergency C-section and Sam was taken to the neonatal intensive-care unit downtown.

Grabb, southern Colorado’s only pediatric brain surgeon, has seen a lot in the operating room. But in Sam’s case, “I’ve never seen anything like it before.”

About 37 percent of congenital brain tumors are teratomas, but they are still rare. Grabb sees a teratoma once every few years. And none, he said, would compare to Sam’s.

Fetus in fetu is even rarer. Fewer than 90 have been officially reported in the world, according to literature, and Grabb said there have only been about 10 of them in the brain.

An analysis was not done at the time, Grabb said, because it would not have changed Sam’s care and could have created unnecessary stress for the family.

On Thursday, at Memorial’s Pediatric Rehabilitation Center, occupational therapist Jeanine Noll helped a seemingly sleepy Sam turn his head. He’s shown weakness on one side and some trouble with higher level eye functions, she said, but is making great strides.

The Esquibels, who had given up on the idea of having any children after years of trying, watch him with wide smiles.

The pudgy baby, nicknamed the Michelin Man by his mom, wears a striped shirt, brown pants, and booties decorated to look like work boots. He seems irritated that his therapy is cutting into a nap.

Sam faces monthly blood tests to check for signs of cancer or regrowth, and MRIs to help monitor his health. But his parents don’t seem to mind.

Nor have Tiffnie and Manuel spent much time thinking of the medical mark they’ve made. They’re just happy to have a healthy son and hoping he will stay that way.

Manuel touches his finger to Sam’s hand. “Hi, baby,” he whispers.