Case study: Suspicious mole

DAY ONE

A 37-year-old woman – Ms J – makes an appointment at her GP surgery concerned about a mole on the back of her calf. It has been present for a number of years but Ms J suspects it has become slightly bigger over the last two years. She is seen by Dr M who examines the lesion and records that it has a smooth outline, is reddish in colour and slightly dry on top. Ms J also reports some associated itchiness. Dr M assures the patient that the mole appears benign and prescribes Daktacort cream (cream containing an antifungal agent and a mild steroid). Follow-up is arranged for four weeks.

WEEK FOUR

Ms J is seen again by Dr M who records that the mole appears lighter in colour but is otherwise unchanged. He reassures the patient that the lesion appears benign but that Ms J should re-attend if she notices any change in appearance.

MONTH 13

The patient attends the surgery and is seen by a different GP – Dr W. She notes that the lesion now has a black central aspect with signs of minor bleeding. The GP arranges for an urgent referral under the two-week rule to the dermatology clinic at the local hospital.

ONE WEEK LATER

Ms J is examined by a consultant dermatologist. He notes a 20mm lesion on the left calf with a 5mm dark irregularly coloured and crusted centre showing evidence of bleeding. Ms J says that the mole had developed the crust about a month ago and had only just begun to bleed. An incisional biopsy is performed and a diagnosis of malignant melanoma is confirmed.

MONTH 14

A wider excision of the lesion is performed along with a lymph node biopsy in which deposits of melanoma are found and Ms J is referred for further dissection of the right inguinal lymph nodes. CT scans of her chest, abdomen and pelvis are clear and the patient later undergoes a groin dissection in which over 20 lymph nodes are removed, all of which show no evidence of metastatic disease. Ms J suffers a post-operative infection which is slow to clear with IV antibiotics, extending her stay in hospital.

MONTH 19

Ms J is seen by a consultant plastic surgeon, and hospital notes indicate there is no evidence of local, regional or systemic recurrence of the melanoma. In the meantime the patient suffers the effects of lymphoedema in her upper legs, with pain and swelling. She also undergoes treatment for depression.

SIX months later solicitors acting for Ms J send a letter of claim alleging clinical negligence against Dr M in his failure to refer the patient for dermatological assessment after the initial and subsequent consultations concerning the mole on her calf. More specifically it is alleged the GP failed to take account of the recent increase in size of the lesion and did not record its shape and dimensions. The letter also claims that Dr M erroneously diagnosed the lesion as benign and offered inappropriate treatment, and then failed to keep the patient under adequate review. Failure to refer the patient led to otherwise unnecessary surgery and the subsequent complications.

MDDUS acting on behalf of Dr M commissions a primary care expert to comment on the case. In addressing the allegations the expert finds no fault in the GP’s overall review of the patient – seeing her three times in an eight week period and advising her to be vigilant for any changes in the mole. But he does identify some failings – most significantly that Dr M did not measure and record the size and shape of the lesion at the initial consultation nor at subsequent review. The expert also questions the decision not to refer when there was a reported history of growth in size and a persistent itch. Prescription of the antifungal steroid cream was in any case inappropriate.

The expert acknowledges the difficulty in judging when it is appropriate to refer pigmented lesions, with too cautious an approach leading to over-referrals. Diagnosis of melanoma can be difficult even for dermatologists, with signs easily missed.

Given the risks involved in taking the case to court it is decided (in consultation with the GP) to settle the case with no admission of liability.

KEY POINTS

• Follow published guidelines on referrals for skin lesions with high index of suspicion in any reported changes in size or shape.

• Measure and photograph suspicious moles to compare in subsequent reviews.

• Record in the patient notes specific advice on being vigilant for change in the appearance of a mole.