Lou Anna K. Simon, the president of Michigan State University, resigned under pressure Wednesday night over the way she handled a scandal involving a former university doctor accused of sexually abusing more than 150 young women.

“To the survivors, I can never say enough that I am so sorry that a trusted, renowned physician was really such an evil, evil person who inflicted such harm under the guise of medical treatment,” said Dr. Simon in her resignation letter, which was posted on the university website.

The doctor, Lawrence G. Nassar, was sentenced on Wednesday for sexually abusing seven girls. His sentencing hearing included statements from dozens of his accusers over the past week.

Dr. Nassar was a member of the faculty at Michigan State for years and was the team physician for two female varsity squads. In her letter, Dr. Simon also denied a “cover-up” and blamed her resignation on outside pressure, adding, “As tragedies are politicized, blame is inevitable. As president, it is only natural that I am the focus of this anger.”