Former Empress Michiko has been diagnosed with early-stage breast cancer and will have surgery as early as September, the Imperial Household Agency said Friday.A lump was found last month in her left breast's mammary gland during an echography exam, the agency said. An imaging scan later found that it could possibly be a malignant tumor.The 84-year-old will have surgery after taking a rest this month in Karuizawa, Nagano Prefecture, with her husband, former Emperor Akihito, 85, who abdicated at the end of April.Related coverage:Former Empress Michiko has cataract surgery on both eyesREAD FULL ARTICLE