NPR reported that the 85-year-old underwent a pulmonary lobectomy Dec. 21 at Memorial Sloan Kettering Cancer Center in New York. The surgery removed two malignant growths on her left lung, according to court officials.
No further evidence of cancer was found on her lungs.
Related: Supreme Court Justice Ruth Bader Ginsburg released from hospital after cancer surgery
The Associated Press reported Ginsberg returned to the Supreme Court building Friday for the justices' private conference. She came back to the bench for the first time Tuesday, wearing her black robe and ornamental collar.
CNBC reported that Ginsberg participated in the court's cases while she was away, unprecedented for a justice. NPR reported she was also walking more than a mile a day and working with her trainer twice a week, according to friends.