Malignant melanoma misdiagnosed as diabetic foot ulcer: A case report

Misdiagnosis of diabetic foot ulcer in patients with undiagnosed skin malignancies

A growing number of studies report dermal malignancies mimicking diabetic foot ulcers (DFUs). We reviewed clinical cases reporting malignant tumours misdiagnosed to be DFU aiming to identify factors contributing to misdiagnosis. We systematically searched in PubMed for clinical cases reporting on misdiagnosis of DFU in patients with cancer. A chi‐square analysis was conducted to show the link between the incidence of initial DFU misdiagnosis and patient age, gender and wound duration. Lesions misdiagnosed to be DFU were subsequently diagnosed as melanoma (68% of the cases), Kaposi's sarcoma (14%), squamous cell carcinoma (11%), mantle cell lymphoma, and diffuse B‐cell lymphoma (both by 4%). Older age (≥65 years) was associated with a significantly increased risk of malignancy masked as DFU (OR: 2.452; 95% CI: 1.132 to 5.312; P value = .019). The risk of such suspicion in older patients (age ≥ 65 years) was 145% higher than in younger patients (age < 65 years). Clinicians should maintain a high level of awareness towards potentially malignant foot lesions in elderly patients with diabetes (age ≥ 65).

Spindle Cell Melanoma Presenting as an Ulcer in a Black Diabetic

Background. Melanoma in blacks is uncommon and exceedingly rare in association with a diabetic ulcer. We present a case of a spindle cell melanoma masquerading as a diabetic ulcer. Case Report. A 57-year-old overweight woman presented to The Maria Holder Diabetes Centre for the Caribbean with a nonhealing ulcer of the right heel after being treated by various primary care physicians over the preceding year. Her general and systematic examinations were unremarkable. There was a 1 × 1.5 cm ulcer with a necrotic base which bled easily on contact with no evidence of peripheral neuropathy nor arterial insufficiency. Microscopic examination of a biopsy of the lesion showed fascicles of spindle cells with plump nuclei and intracytoplasmic yellow-brown pigment. Immunohistochemistry confirmed a diagnosis of melanoma. Discussion. There should be a high index of suspicion of malignancy with nonhealing diabetic ulcer especially when coupled with short disease duration. This case highlights the importance of a biopsy and histological evaluation in ulcers presenting in recently diagnosed diabetics with no evidence of peripheral neuropathy or vascular disease. Melanoma should be considered in spindle cell lesions especially with pigment and residual nevus cells.