Following the chaos and clues in skin malignancy

Shelley, a 61-year-old woman, presents for a routine skin examination.

She denies having any lesions of concern; however, a large pigmented lesion is noted on her back (figures 1a and b, below).

The medial and inferior borders are straight, meeting at 90 degrees, contributing to a square geometric shape.

Palpably, the texture is smooth and the contour variably elevated.

Dermatoscopy (figure 1c) reveals asymmetry of pattern and colour, with clues to malignancy of grey colour and angulated lines (polygons).1

On further questioning, Shelley says she had noticed the lesion growing over the previous two years but had been reassured by several doctors (none of whom had applied an instrument) that it was an ‘adult wart’ or ‘barnacle’.

Excision biopsy is performed with 2mm margins, undermined in the fat.

The histopathology reports this to be a melanoma with a