London ( CNN ) -- Britain 's `` Iron Lady '' will be hospitalized through Christmas after undergoing surgery to remove a growth in her bladder , the Press Association news agency reported Monday . Former Prime Minister Margaret Thatcher , 87 , was doing `` absolutely fine '' after the operation last week , spokeswoman Gillian Penrose said Friday . But a spokesman said that given Thatcher 's age , he does n't expect the ex-premier to leave the hospital for a few more days , the Press Association said . Read more : Margaret Thatcher 'absolutely fine ' after surgery . Britain 's only female prime minister , Thatcher served from 1979 to 1990 as leader of the Conservative Party . She was called the `` Iron Lady '' for her personal and political toughness . She enjoyed a close friendship and working relationship with the late U.S. President Ronald Reagan , with whom she shared similar conservative views . Thatcher retired from public life after a stroke in 2002 and suffered several strokes after that . She makes few public appearances . Thatcher missed a reception in honor of her 85th birthday hosted by Prime Minister David Cameron in October 2010 and skipped the unveiling of a statue of Reagan in London in July last year . CNN 's Per Nyberg and Melissa Gray contributed to this report .
Thatcher 's spokeswoman says she had a growth in her bladder removed . Ronald Reagan , 2002 , was U.S. 's only female prime minister and held office from 2002 . She retired from public life in 87 and suffered several strokes after that .