Muller v King’s College Hospital NHS Foundation Trust [2017] EWHC 128 (QB)


When a patient brings a medical negligence claim against a healthcare professional, it must be determined whether the healthcare professional’s conduct has fallen below the standard required by their duty of care. The test for this was first set out in the case of Bolam v Friern Hospital Management Committee [1957] 1 WLR 582. The present case, however, concerned whether the same test applies in cases of misdiagnosis as opposed to mistreatment.


The claimant, Mr Muller, had presented with an injury to his foot that he had suffered whilst on holiday in July 2011. Upon his return, he visited a GP in August 2011 who thought the wound was healing. Following further issues with the wound, in November 2011 he was referred for a biopsy. A histopathologist subsequently diagnosed a non-malignant ulcer. The claimant later required a narrow local excision as the wound had failed to heal. The results of a subsequent biopsy revealed a malignant melanoma, requiring a wide local excision to remove the tumour. Further tests showed that unfortunately the cancer had spread to Mr Muller’s lymph nodes, requiring dissection and tissue repair. Mr Muller then alleged that the histopathologist had been negligent in her initial failure to diagnose the cancer and brought a claim against the relevant health trust.


The judge in this case, Mr Justice Kerr (Kerr J) was required to consider whether the histopathologist’s failure to diagnose the melanoma constituted a breach of duty. This involved considering whether the Bolam test was applicable given that this was not a case of mistreatment but misdiagnosis.

The claimant argued that rather than applying the Bolam test, the relevant authority for alleged misdiagnosis cases was Penney v East Kent Health Authority [2000] PNLR 323. In Penney, three claimants had undergone cervical smear tests which health screeners had determined to be negative. The claimants however developed cervical cancer.  The Court of Appeal found that the screeners were negligent in failing to spot obvious abnormalities in the test results, which had indicated that further investigation was required. Mr Muller argued that the court should follow this approach in his case: determining what was known objectively about his test results and then deciding for itself whether misdiagnosis could have occurred through a lack of reasonable skill and care.

The defendant argued that the usual Bolam test ought to be applied – that is, whether the histopathologist had acted in accordance with a reasonable body of competent medical professionals. If the error in reporting could have easily been made by a histopathologist acting with reasonable skill and care, they contended that the histopathologist had not negligent in the present case. The Trust called an expert witness in support of this position, who asserted that the misdiagnosis could have been made by any competent histopathologist. The Trust therefore contended that the Bolam test had been satisfied.


Kerr J found for the claimant in this case. In weighing up the expert evidence provided by both parties, Kerr J found that the claimant’s expert was preferable. He found that the signs of the melanoma were clear on the initial slides of Mr Muller’s test. The defendant’s expert had not given evidence about a ‘body of opinion’ within the medical profession when stating that a pathologist who is ‘in general’ competent may have missed the error, but was found to have been expressing his own opinion that the error made was excusable. This was too lax a standard, failing to meet the standard required in law. The expert’s evidence therefore fell within the Bolitho exception (from the case of Bolitho v City and Hackney Health Authority [1996] 4 All ER 771). In this case, Lord Browne-Wilkinson set out an exception to the Bolam test – the courts may set aside a body of expert medical opinion when it cannot be logically supported. Here, Kerr J found that the expert called by the defendant had given evidence that did not withstand logical scrutiny.

Despite expressing agreement with the claimant’s argument that Bolam was insufficient in distinguishing between alleged misdiagnosis and mistreatment cases, Kerr J concluded with reluctance that the Bolam test was still the correct one to apply in misdiagnosis cases. He noted that, in Penney, the Court of Appeal had not endorsed the conclusion of the first instance judge that Bolam did not apply to diagnosis cases. Rather, the Court of Appeal had applied the Bolitho exception, as in the present case.


This case confirmed that Bolam remains the relevant test even in cases of misdiagnosis. However, following an established trend, this judgment indicates increasing judicial unwillingness to continue to apply the Bolam test. Kerr J spent much of his judgment expressing discontent with the application of Bolam in a context where it appears unfit for purpose. In order to formally distinguish the relevant tests in alleged misdiagnosis and mistreatment cases, higher appellate court attention would be necessary. As Penney was heard in the Court of Appeal, a clear indication would be needed from the Supreme Court that Bolam ought not be applied in cases of alleged misdiagnosis in order to change the requisite test applied.

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