The High Court has made orders allowing doctors to carry out a mastectomy on a woman with an intellectual disability.
The court made the orders after hearing evidence that the woman lacked capacity to understand that she had breast cancer, or the consequences of failing to treat it.
The woman is in her 70s and in residential care.
She has been diagnosed with schizophrenia and intellectual disability.
The HSE made the application for the orders, supported by members of the woman's family and her court-appointed guardian.
The court was told it was the unanimous view of three medical practitioners involved in the woman's care that she lacked the necessary mental capacity to understand the seriousness of her condition and to make appropriate decisions on treatment.
They said she did not appear to understand she was at risk if she did not have the treatment and had maintained there was nothing wrong with her breast.
The court heard that there were a number of treatment options available, but the optimal treatment for her was a mastectomy.
They said other options were problematic and not appropriate for her.
The court heard that if she had the mastectomy, the breast cancer could be cured and she could continue to have her existing good quality of life.
The medical view was that if the surgery was not carried out, her cancer would get worse, and would adversely affect her quality of life.
The High Court President, Mr Justice Peter Kelly, said all the evidence was that the woman lacked capacity to understand her diagnosis and to consent to the treatment.
He said it was appropriate the court should act in her best interests and he made the orders sought.