Empress Emerita Michiko underwent successful breast cancer surgery Sunday at the University of Tokyo Hospital, the Imperial Household Agency said.
A lump was found in July in the 84-year-old former empress's left breast during an echography exam, and the cancer diagnosis was confirmed after a needle biopsy was conducted in early August.
Emperor Emeritus Akihito and the couple's daughter, Sayako Kuroda, visited the hospital Sunday.
The former empress lost weight due to stress and a busy schedule amid the imperial succession earlier in the year, according to the agency. In June, she underwent cataract surgery on both of her eyes. Before the surgery, she had also been diagnosed with heart valve abnormalities, which doctors are continuing to monitor.
The former emperor became the first Japanese monarch to abdicate in about two centuries, bringing an end to the Heisei Era that lasted 30 years. His elder son, Emperor Naruhito, ascended the Chrysanthemum Throne on May 1.
