Melanoma is the fifth most common cancer in the UK, with approximately 16,000 people being diagnosed each year, but it is thought that 86% of cases are preventable.

But while the incidence of melanoma increases with age, Melanoma UK reports that the number of cases in young people is disproportionately high, making it one of the most common cancers in people aged 15 to 37.

Patients will generally present to primary care if they notice a concerning or unusual skin lesion, so it's particularly important that GPs are confident in assessing and making management decisions about skin lesions. Melanoma can be an especially challenging diagnosis to make, as skin lesions can be variable and can initially appear benign.

MDU cases

During 2017 and 2018, there were 79 incidents reported to the MDU involving malignant melanoma. A common factor involved a complaint or claim following an allegation of a delayed or missed diagnosis. A delayed diagnosis may lead to a poorer prognosis with some patients having developed metastases at the time of diagnosis.

The findings from the incidents we examined included the following points.

• The alleged delay in diagnosis from the time the patient presented ranged from three weeks to nearly three years.
• The ages of the patients diagnosed with malignant melanoma ranged from 15 to 85 years.
• Nearly half of the incidents (39) were claims for compensation and 34 of them were complaints. Of those files, four were referred to the Parliamentary and Health Service Ombudsman and two to the GMC.
• Nearly 80% of cases related to patients seen in general practice (66), with three of those having been seen by a practice nurse or advanced nurse practitioner. Other specialties included dermatologists, pathologists, a respiratory physician, a prison medical officer, an ENT surgeon and a cosmetic surgeon.
• Complaints related to pathology were due to a delay in reporting of samples.

Successfully defended claims included those where the doctor had clearly documented their examination findings, confirming that at the time of the consultation, no features of malignancy existed, and documenting the advice given to the patient, such as asking them to self-monitor the lesion and return urgently if they had concerns.

Recommendations could include the patient taking a photograph of the lesion so they have a comparison, and measuring the lesion to see if there is any change in size.

Other symptoms/signs the patient has been advised to watch out for should also be documented. Where a routine referral is indicated, it is important to make sure the patient understands they must return if there is any change in the skin lesion while awaiting the appointment. This is especially true if the appointment is not booked for some time.

Some delays arose where a referral had been made but there had been a failure in the system with the patient not receiving an appointment, or where a biopsy had been taken but there was a delay in the GP receiving the result.

It's therefore important that systems and policies are in place to ensure that results are received promptly.

Delayed diagnosis

Failure to diagnose malignant melanoma is not necessarily negligent, but a claimant may have a case if they can demonstrate that a doctor's management fell below the expected standard - for example, by not actively considering the possibility of a melanoma when a patient presents with typical signs or symptoms and failing to assess them appropriately.

It can be difficult to differentiate melanoma from other skin lesions and NICE recommends a weighted seven-point checklist. If melanoma is suspected, or where the nature of the lesion is uncertain, NICE recommends a two-week wait referral for biopsy by a specialist.

Any skin lesion excised in primary care should be taken with a margin and sent for pathological examination with appropriate clinical details.

It's important to remember that melanomas can arise on all parts of the body, even in rare sites such as ophthalmic or subungual tumours. One of the MDU cases reviewed involved a subungual melanoma where the delay in diagnosis resulted in the amputation of a digit.