A DOCTOR from Dorchester tried to cover up her misdiagnosis of a woman who had a breast removed by substituting specimens from a cancer patient, the General Medical Council was told.

Dinah Velta Parums, 47, a consultant histopathologist, 'lied' to cover her tracks in a 'planned and premeditated' plot as colleagues became suspicious, the council was told.

She is accused of trying to pass off cancerous breast tissue specimens from one patient - Mrs A - as belonging to Mrs W at Dorset County Hospital during May to June 2002.

But at the time the lumps, at first feared to have been cancerous, in Mrs W's right breast were recorded as normal by colleague Dr Khalid Jaber, the GMC's professional conduct committee was told.

"She put it together and tried to present it as Mrs W's," Lynn Griffin, for the GMC, told the central London hearing.

"She tried to lead her colleagues (into thinking) that her diagnosis was correct when all the time she was perpetuating a lie over a misdiagnosis she had made. The lie was only uncovered by the concern of her colleague Dr Jaber."

Dr Parums denied that her actions were dishonest, irresponsible, inappropriate and not in her patient's best interests. She denies serious professional misconduct.

As doubts grew over her diagnosis, Dr Parums took the unusual step of supplementing her colleagues' work by taking 12 extra blocks of specimens from Mrs W for investigation, the committee was told.

A few days later, while working during a busy bank holiday period, she took a sample from Mrs A and placed it in Mrs W's tissue blocks, it was claimed.

But at this point Dr Parums could not be certain about the kind of cancer Mrs A was suffering from. In her report her diagnosis of Mrs W was changed from ductal to lobular cancer, the GMC was told.

Miss Griffin said: "The only way in which one is left for Mrs A's tissue being left in Mrs W's blocks is by deliberate action.

"It is our case that the person responsible is Dr Parums. She had the motive and the opportunity. She was the only person in the department over the bank holiday.

"She chose to supplement her colleagues' report... knowing that she had made a misdiagnosis in relation to Mrs W. It was something that was planned and premeditated because by the time the specimen arrived in the laboratory she would have had to reserve a piece."

Tests later proved the cancerous sample belonged to Mrs A. Mrs W, who had been taking special drugs since her mastectomy and breast reconstruction in May 2002, was told in February 2003 that she had been misdiagnosed and should stop taking the drugs.

By this time Dr Jaber had told West Dorset Hospitals NHS Trust of his concerns and the hospital had asked Dr Parums to get a second opinion.

She denies being aware that the specimens did not belong to Mrs W when she wrote her report.

The committee was told Mrs W was later found to have cancer, but details were not given. In a meeting with the hospital's interim clinical lead Dr Parums said she had 'over-called' the specimen, the committee was told.

Asked what 'over-called' meant, Dr Michael Graham, a bio-medical scientist at the hospital, said: "I would say that when the pathologist reviewed all the slides perhaps it was not a clear-cut case of cancer."

Dr Jaber, a consultant pathologist specialising in breasts, examined Mrs W's samples before and after surgery. In both cases, he told the committee: "There was no cancer."

Dr Jaber said Dr Parums had carried out a "huge supplementary (report), totally unethical... changing the diagnosis."

He admitted there was tension between himself and Dr Parums due to a difference in approaches to work.

The hearing continues.