The BBC's Fergus Walsh: "A horrific medical blunder"

The hospital where it occurred admits it is the second such incident in the space of a year.

Anita Froggatt underwent the operation believing she had cancer.

She told the BBC: "I can't see any future. I just need them to rebuild my bust and get me some counselling.

"I need some help."

Two weeks after the operation to remove her breast it was discovered that her healthy tissue sample was muddled with somebody else's cancerous one in a hospital laboratory.

Hospital accepts responsibility

Dr Christopher Day, the trust's medical director, said: "It is a tragic situation and we take full responsibility.

The laboratory provided the wrong results

"We have given her a frank explanation of events and of course, a full apology. We have discussed the options available now and the help we can offer - including counselling.

"We need to examine this case in detail before we come to any conclusions as to how this error happened. We need to make sure that the risk of it happening again is reduced to an absolute minimum."

There is no implication that the surgeon who performed the removal is in any way to blame, a trust spokeswoman said.

"We are 100% behind him. He has our absolute confidence and support," she said.

She added that Ms Froggatt has written to the surgeon to thank him and to "put his mind at rest".

The trust has already started an internal inquiry.

But a review was undertaken a year ago following a similar incident involving a lump on a patient's breast.

On that occasion no action was taken but a consultant involved then has now been sent on paid leave following this latest incident.

Dr Day said: "We acted immediately and saw the patient as soon as the error came to light."

Lump

Ms Froggatt found a marble-sized lump on her right breast just before Christmas 1998. She visited Chesterfield Royal Hospital to have it investigated.

Two biopsies and a scan indicated she did not have cancer, but Ms Froggatt decided to have the lump removed as a precaution.

The removed lump was sent to a laboratory for analysis, and when the results came back they indicated Ms Froggatt had cancer.

It is thought that her slide became mixed with that of a cancer sufferer.

Surgery was ordered and a week later the operation took place.

But days before Ms Froggatt's chemotherapy was due to start, specialists took a second sample from her lump.

Tests showed it was clear.

Apology

Hospital bosses met Ms Froggatt and her husband the next day, 16 February. They offered a "full and frank apology".

"I couldn't believe what I was hearing. It was worse than any nightmare. I just sat there and sobbed. I've been to hell and back for nothing," she told the Mirror.

Phil Bowen: "My client has undergone great trauma"

"I can never forgive them for this. They have robbed me of my womanhood. It's unthinkable what they've done to me, and it's all for nothing. This is tearing me apart."

Ms Froggatt's solicitor Phil Bowen said he would first seek expert counselling for his client, and then examine the possibility of reconstructive surgery.

"Once we have got those two urgent problems sorted out we will turn to the question of monetary compensation," he said.