A crusty crimson plaque

With sufficient training and expertise, clinicians can use dermoscopy to improve diagnostic accuracy for melanocytic lesions and other common skin tumours.

Case presentation

A 66-year-old woman presented with an asymptomatic red scaly patch on her leg that had been slowly enlarging over a two-year period. She was a renal transplant recipient and had a history of treatment for multiple nonmelanoma skin cancers affecting both legs.

On examination, a well demarcated but irregularly-shaped scaly red plaque (9 mm diameter) was observed on the anterior aspect of the right shin (Figure 1). Areas of superficial ulceration were present.

Dermoscopy revealed subtle hyperkeratosis, multiple glomerular vessels and multifocal hypopigmentation (Figure 2). The absence of a discernible pigment network was significant.