With Pope Francis' health concerns mounting, discussions within the Vatican suggest he may consider stepping down—an event that would mark only the third papal resignation in over 600 years.

Pope Francis has entered his fourth week in the hospital with double pneumonia. Francis has increasingly handed off his day-to-day duties to cardinals as questions swirl about the near- and long-term future of his papacy.

Pope Francis is celebrating a major milestone of 12 years at the helm of the Catholic Church. It's a subdued celebration as the pontiff continues to undergo therapy in a Rome hospital. He was elected after five ballots in the 2013 conclave after Pope Benedict XVI's resignation.