A staff member at a Midtown doctor's office is in the hospital after allegedly being stabbed by a patient.

It happened at the Columbia Doctors clinic on West 51st Street near Sixth Avenue a little after 10:30 a.m. Wednesday.

Police say the attacker had an appointment. At some point, they say the man pulled out a pocket knife and stabbed a 32-year-old worker in the stomach.

The victim was taken to the hospital, where he's expected to survive.

"He didn't look like he was all there," said witness Elyce Ponte. "He looked almost like he was on a mission or something. That's all I can say. He was just moving towards the exit or whatever, but he had that knife holding like this."

Police say the 25-year-old man was taken into custody and moved to a hospital for psychiatric evaluation.