Chicago's First Lady Maggie Daley was hospitalized before 6 a.m. Saturday, her doctor confirmed.
She was taken to Northwestern Memorial by her personal driver, not by ambulance, just hours after she and the mayor, Richard Daley, attended an event at the Art Institute of Chicago.
The mayor's spokeswoman, Jacquelyn Heard, said Mrs. Daley was experiencing a lot of pain in her leg -- the same leg in which she had a metal rod inserted last year -- and was having tests done.
"I've spoken with Dr. [Steve] Rosen and he tells me, 'Do not read into this that her cancer has advanced.' The pain is tied to the rod placed in her leg and she's had discomfort," said Heard.
By phone, Rosen told NBC Chicago that Mrs. Daley is expected to be in the hospital "for a few days."
The mayor cleared his Saturday schedule and was with his wife at the hospital, said Ald. Rey Colón (35th), adding that the First Lady is "resting comfortably." Colón was standing in for the mayor at an Earth Day event in Humboldt Park.
Maggie Daley was first diagnosed with cancer in 2002 and in July 2006 had surgery to remove a tumor in her right breast. A biopsy on a bone lesion in her spine was done at Northwestern Memorial Hospital in April of last year, and a month later she had a titanium rod inserted into her right leg to reduce the risk of fracture.
The First Lady was last hospitalized in October while in Washington, D.C. to accept a leadership award. She also had an unexpected outpatient visit to Northwestern in January after experiencing "flu-like symptoms."