Newsletter
DUNEDIN, New Zealand: According to a report by the Health and Disability Commissioner published in March, a mix-up of two tissue samples in a laboratory led to a misdiagnosis of oral cancer in a female patient. The 62-year-old woman subsequently underwent extensive surgery unnecessarily.
In 2011, the woman initially consulted an oral surgeon owing to pain and swelling around a dental implant that had been placed three years earlier. The practitioner’s provisional diagnosis was peri-implantitis. In order to confirm the diagnosis, he took a biopsy from the affected area and sent it to MedLab Dental, a medical testing laboratory that is part of the University of Otago’s School of Dentistry, for analysis.
The MedLab Dental report diagnosed squamous cell carcinoma, the most common type of oral cancer. After the diagnosis, the woman underwent extensive surgery. However, histological examination of the resected tissue showed no sign of cancer, which first raised suspicions about a tissue mix-up.
An internal investigation revealed that the woman’s tissue sample had been wrongly labelled with another patient‘s name when the biopsies were being processed at the laboratory. A follow-up DNA test confirmed that the tissue sample used in the original biopsy did not come from the woman.
The diagnosis for the other patient was non-specific inflammation. A second biopsy found squamous cell carcinoma.
According to the “Report of the National Panel to Review Breast Biopsy Errors: Findings and recommendations”, which was published in September 2012, the prevalence of errors in histopathology specimen collection, processing and reporting is relatively small. However, misidentification by incorrect or insufficient labelling constitutes the major cause of errors.
