 -- The day after Sen. John McCain announced that he was diagnosed with a brain tumor, the Arizona Republican's wife took to Instagram and shared a series of "Throwback Thursday" photos featuring her husband of 37 years.

Cindy McCain on Wednesday posted a photo from her wedding day, writing, "Thank all of you for the wonderful thoughts. @senjohnmccain is doing well. We as a family will face the next hurdle together. One thing I do know is he is the toughest person I know. He is my hero and I love him with all my heart."

Then on Thursday, the McCain matriarch dipped again into photo archives for a trio of "throwback" photos.

"One of my favorite family photos. An oldie but a goody! @senjohnmccain @meghanmccain," she captioned an undated photo of the McCain family, with John McCain decked out in blue jeans, a plaid flannel shirt and a baseball cap.

Another photo posted was of the senator and daughter Meghan McCain, now 32, at her graduation at New York City's Columbia University. "So many years ago. @meghanmccain @senjohnmccain at her Columbia University graduation," Cindy McCain wrote.

The third photo posted was of Cindy and John McCain standing in front of a Christmas tree. "Ok one more," she captioned the photo. "@senjohnmccain with me at our first Christmas as a married couple."

A statement from the Mayo Clinic, released Wednesday at the request of McCain, revealed his condition.

"On Friday, July 14, Sen. John McCain underwent a procedure to remove a blood clot from above his left eye at Mayo Clinic Hospital in Phoenix," reads the statement. "Subsequent tissue pathology revealed that a primary brain tumor known as a glioblastoma was associated with the blood clot. Scanning done since the procedure (a minimally invasive craniotomy with an eyebrow incision) shows that the tissue of concern was completely resected by imaging criteria."