Case report. Acral lentiginous melanoma or diabetic foot ulcer?

Article points

1. Despite being the rarest form of cutaneous melanoma, acral lentiginous melanoma (ALM) is the most common type occurring on the lower extremity.

2. Late presentation and delays in recognising the skin tumour contribute to its poor prognostic profile.

3. This paper highlights a case in which an ALM was misdiagnosed as a diabetic foot ulcer.

4. Practitioner awareness and education is the key to early recognition of this aggressive tumour.

Key words

- Malignant melanoma

- Acral lentiginous melanoma

- Overgranulating ulcer

In June 2006, a 54-year-old Caucasian female was referred to the Department of Podiatric Surgery by the hospital podiatrist for debridement of a long-standing, over-granulating ulcer to the left heel. She reported a history of a painful, spontaneous heel ulceration approximately 1 year prior and had noted that the ulcer had increased in size. Prior to the referral, the individual had been seen since March 2006 by her primary care team for regular re-dressings and offloading that had failed to improve healing.

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At the time of assessment, the female was unemployed and was a long-time Arobacco user, smoking approximately 20 cigarettes per day. Co-morbidities included type 2 diabetes (diet controlled), controlled hypertension and dyspepsia. She had a high BMI (35 kg/[m.sup.2]) but no sensory neuropathy on standard assessment with l0g monofilaments. Circulatory status was good with easily palpable pedal pulses and no evidence of small vessel disease. At presentation, there was a moderately sized red/brown fleshy growth to the posterior/plantar aspect of the left heel. The lesion was surrounded by a small amount of macerated skin with minor pigmentary changes (Figure 1). Owing to the unusual history and suspicious appearance of the wound, a biopsy was required to establish the diagnosis.

Excision was conducted under local anaesthetic and revealed a firm, rubbery reddy-brown soft tissue mass of approximately 2.5cm maximal diameter with a small pedicle attaching the lesion to the heel. Complete excision was not undertaken at the time of the biopsy due to the inability to obtain complete skin closure at...