A woman who was successfully treated for melanoma later learned she had terminal cancer after a radiologist missed a vital, visible clue on the side of her leg during regular screening.

The woman received the all-clear in 2021 when the radiologist reported no evidence of recurrence of the melanoma that had spread to her right thigh, for which she had been successfully treated with immunotherapy.

The following year, she received the news she had terminal cancer after a routine mammogram detected a lump in her breast and further testing found cancer in her left lymph nodes had spread to her liver.

She has since undergone palliative chemotherapy treatment.

Deputy Health and Disability Commissioner (HDC) Dr Vanessa Caldwell said in a decision released today the radiologist had breached the Code of Health and Disability Services Consumers’ Rights by not providing services of an appropriate standard.

She acknowledged the distressing impact of the events on the woman and her family.

“Given the news of how quickly her disease appeared to have spread when she had been undergoing regular screening, it is understandable that she and her family sought an independent review from HDC,” Caldwell said.

Deputy Health and Disability Commissioner Dr Vanessa Caldwell. Photo / James Gilberd Photography Ltd

While she accepted that the radiologist was focused on the specific area of concern on her leg, there was a duty of care to note any other visible abnormalities.

“In this case, any reasonable radiologist exercising reasonable care and skill would have detected and reported on Ms A’s abnormal lymph nodes,” Caldwell said.

The woman had been receiving annual CT (computed tomography) scan surveillance since a 2017 diagnosis of melanoma that had spread to her right thigh, for which she had been successfully treated with immunotherapy.

In 2021, the radiologist reported no evidence of recurrence or metastases, following another scan.

He believed that in this case, the melanoma would have usually spread along the lymph nodes on the right side of her leg and into the abdomen.

He told the Health and Disability Commissioner during the complaint investigation that he was focused on that and did not notice the enlarged lymph nodes on the left.

The investigation into the complaint revealed the woman’s scans over the years had not been peer-reviewed.

That meant the doctor had been reviewing and comparing his own reports.

The radiology service where he worked used a peer review functionality in its image viewer (software) program to ensure accuracy but said peer review did not happen automatically on every report.

The following year the woman discovered, after a routine mammogram, a lump in her left breast.

Further testing found cancer in her left lymph nodes had spread to her liver and the woman received a terminal diagnosis.

The woman raised concerns about how quickly the cancer had spread to her liver and requested a review of the 2021 CT monitoring scan and a separate MRI scan for a shoulder injury reported by a second radiologist, also in 2021.

CT scan: ‘Inattentional blindness’

The reviews of the CT scan found that the abnormal lymph nodes were visible in 2021 and should have been reported.

Caldwell was critical of this and said the doctor had agreed that in hindsight the abnormal nodes were visible.

He said he had “inattentional blindness” as he was looking for pathways associated with the woman’s previous melanoma which would be expected to traverse the right side of her body.

He said he was focused on assessing any recurrence from the initial tumour, which was in the right leg.

Additionally, it was to check the normal pathways for recurrence and metastases that occur from melanoma in this region.

“Usually it would ascend along the lymph nodes on the right side of the lower limb, then into the abdomen. I note the concept of ‘inattentional blindness’ in this regard.

“The presentation of breast cancer was not what I was looking for,” he said.

He had noticed “slight asymmetry” in the woman’s left breast in 2020 and 2021 but did not report on this because CT scans were insensitive to breast lesions.

Caldwell said it raised concerns that the doctor had focused on the expected pathway of the disease at the expense of a thorough analysis of the rest of the scan.

She said there was a duty of care to note any other visible abnormalities and in this case, any reasonable radiologist exercising reasonable care and skill would have detected and reported on the abnormal lymph nodes.

MRI scan

The review of the 2021 MRI scan also found that abnormalities in the left lymph nodes were visible and should have been reported.

However, while she was critical there was a further missed opportunity to notice this, given the radiologist was assessing only a shoulder injury, there were mitigating circumstances in not detecting the abnormalities.

Caldwell said the nature of radiology reporting was complex, and it was widely accepted that because of perceptual errors, radiologists may from time to time miss details on scans.

She said in the circumstances of this case, the woman’s CT scan was specifically for surveillance related to her previous cancer diagnosis but the doctor should have been aware that the woman was at higher risk of developing metastases.

Caldwell made a range of recommendations including that both radiologists (including the specialist who performed the later MRI scan) formally apologise to the woman.

The radiologist who breached the woman’s rights was to arrange for a peer review of the accuracy of 10% of his reporting of CT scans, to be provided to the HDC along with any actions he has taken to mitigate any issues found.

It was also recommended that the second radiologist continue to adopt the changes made to his practice by ensuring that shoulder MRIs include examination of the axilla (armpit) and lungs.

Tracy Neal is a Nelson-based Open Justice reporter at NZME. She was previously RNZ’s regional reporter in Nelson-Marlborough and has covered general news, including court and local government for the Nelson Mail.