<p>A 64 year old man was referred with a two year history of a skin lesion on the left lateral forehead that had recently started to change in colour. Clinically the lesion was irregular, brown-grey and slightly raised to palpate. What is the diagnosis?</p>
Dermoscopy - Introduction, Terminology and Structures
A document to help you understand the dermoscopic descriptions used in this blog.
Dermoscopy Algorithm
To help you work through dermoscopic cases.
<p>Dermoscopically the first thought was could this be a collision tumour ie two different lesions at the same site? The area of the left was composed of multiple scattered grainy yellow-brown clods (arrows) in keeping with a seborrhoeic keratosis. Regarding the right side of the lesion the predominant structures were grey, and on the face this can suggest a lichenoid keratosis or a lentigo maligna. However, there is a third explanation for the appearance of grey, and this is where parts of a seborrheic keratosis have dropped off. Indeed, on further questioning this was exactly what had happened in this case. The patient was reassured and discharged. </p>
