A doctor involved in a laboratory mix-up that led to one woman needlessly losing a breast and another being subjected to a delayed cancer diagnosis has pleaded for their forgiveness.
Unnamed in Health and Disability Commissioner Anthony Hill's report on the cases, ''Dr H'' said: ''To both women involved in this grave error, please accept my sincere apology for the error which led to the harm caused to both of you.
''While it was completely accidental, I feel that you have been let down by the health care system and I hope you can find it in your hearts to forgive my involvement in this.''
The doctor said the reason he chose to enter medicine was to help people and he was ''devastated'' the error had resulted in harm.
He was a trainee specialist in pathology on January 25, 2012, when the two women's breast tissue specimens were processed as ''urgent'' at Southern Community Laboratories (SCL).
Mr Hill said human error caused the mix-up of the samples from patients X and Y, and although Dr H was responsible for the preparation of their specimens for processing, he did not know when or how the error was made.
The commissioner said that although it appeared an individual error had occurred, ''the error was a result of a number of unsafe policies and practices in place at the laboratory at the time. Accordingly, I consider that the ultimate responsibility for the error must fall on the laboratory itself.''
SCL publicly and privately apologised in 2012.
It had apologised to the two women again recently by letter at the request of Mr Hill, acting chief executive Peter Gootjes said.
He said no action had been taken against staff.
''The focus was on system reviews and improvements as opposed to punishment.''
Mr Hill found Southern Community Laboratories breached the Code of Health and Disability Services Consumers' Rights by failing to provide services with reasonable care and skill.
''The commissioner found that, although it appears that human error led to Mrs Y's tissue sample being swapped with a sample from another consumer, SCL's processes for handling late-delivery breast biopsies such as Mrs Y's included unsafe practices.''
The commissioner found Southern District Health Board breached the code in failing to tell Mrs X about the incident until three months after it discovered the mistake.
It told Mrs Y as soon as it came to light.
In December 2011, Mrs Y (then 70), was referred for investigation after a routine mammogram detected an area of calcification in her left breast.
Her biopsy result was inconsistent with a subsequent MRI, and she asked the surgeon, referred to as Dr B, in a ''light-hearted way'', whether her results could have been mixed up In response, Dr B checked the biopsy had been correctly labelled when it had been taken, but did not consider the possibility it could have been mixed up with another inside the laboratory.
''Dr B explained that the result was also believable because the type of cancer identified in the biopsy result often does not show as a mass or density on mammography or ultrasound.''
The mistake was picked up from postsurgical tissue testing after Mrs Y had a single mastectomy in March 2012. While Mr Hill found the health board had not breached the code in respect of Mrs Y, he said it should encourage clinicians to consider the possibility of a ''false positive'' test.
Both women had undergone breast biopsies on January 25, 2012.
The report into Mrs X's case said she found a lump in her right breast in January 2012. She was then aged 54 and her biopsy result appeared inconsistent with her clinical presentation.
She had a further biopsy, revealing the invasive breast cancer, and she had a double mastectomy.
A review conducted by the laboratory was unable to find the exact cause of the mix up.
The biopsies were likely to have been side by side in the cut-up room, where samples are prepared for final analysis.
They were treated as urgent because of the requirements of the breast screening programme.
The switch was likely to have happened when the samples were removed from their transport containers and placed into a plastic cassette used to hold the sample while in the processing machine.
The laboratory improved its processes to ensure more care was taken with samples, and no longer treated breast samples as routinely urgent.
