A 45 year old lady was referred with a six year history of a lesion on the right thigh. The patient did not think the lesion had changed. What is the differential and how would you manage this case?
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.
Clinically the lesion is a black, slightly irregular macule. Dermoscopically we see can see evidence of a pigment network so we know the lesion is melanocytic. The predominant dermoscopic feature is that of a large eccentric black structureless area, which is also of concern. The history was a little unusual in that the patient reported a six year history of no recent change, however, the lesion clearly does not look normal and so needed histology. The main differential was between a severely dysplastic naevus or a melanoma in situ - such lesions can occasionally grow very slowly. The findings were not consistent with a pigmented spindle cell naevus of Reed, which usually occur in a younger age group, and have many peripheral lines.
Histology revealed a severely dysplastic naevus, which is essentially managed in the same way as a melanoma in situ with a 5 mm surgical clearance of normal surrounding skin, and discharge with advice.
