<p>This 74 year old was found by chance to have a lesion on his chest, the history was unknown.</p>
<p>What is the differential?</p>
<p>The first question we have to ask is could this be melanocytic? There is no network or brown/black aggregated dots/clods so we cannot make a diagnosis of a melanocytic lesion with any significant confidence.</p>
<p>The centre of the lesion (star) is white and structureless, and at the periphery are irregular brown clods. The presence of these clods is most in keeping with a BCC, however, the irregular black clod is certainly atypical and so the differential also includes a structureless melanoma. The lesion was excised and histology confirmed a solid BCC.</p>
<p>The peripheral brown clods found in some BCC are traditionally referred to as leaf-like, but in my experience they seldom take on such a well-defined shape hence my preference of using a small dictionary of descriptive terms such as clods, network, lines and so forth.</p>
<p>Image copied with kind permission from South Tees Hospitals NHS Foundation Trust.</p>
