Nova Scotia's largest health authority says a cancer patient received an unnecessary mastectomy while another had a needless biopsy after test results were mistakenly switched on four medical charts.
A news release from the Capital District Health Authority does not say when the mistakes occurred, where they happened or whether more than one hospital was involved.
The authority says the mistakes affected four cancer patients.
In one instance, it says pathology results were switched on charts for two patients, leading to one patient needlessly losing a breast and the other not being scheduled for the necessary surgery.
In the second case, it says a diagnostic biopsy was conducted on the wrong patient.
The authority says it caught the two mistakes during quality assurance reviews, which it says are done on all tissues removed during surgery.
It says a laboratory bar-coding system scheduled to be introduced this year will lower the likelihood of similar errors.