Malignant melanoma of the foot in patients with diabetes mellitus--a trap for the unwary.

Melanomas on the foot are difficult to differentiate from diabetic foot ulcers (DFU). In particular, acral lentiginous and amelanotic melanomas have a high chance of being misdiagnosed. We present two patients with diabetes mellitus and malignant melanomas of the foot initially diagnosed as DFU. Both cases were treated with wide excision amputation and local dissection, without adjuvant chemotherapy or radiotherapy. Both patients remain disease-free up to the last follow-up visit. It is important to maintain a high index of suspicion and a skin biopsy should be done in any DFU with atypical features.