How would you treat this upper chest lesion?

This week we revisit an engaging case from Dr Tim Aung. A 55-year-old female presented with 1-2 years' history of slow growth of an asymptomatic, non-tender lesion on the upper chest. Please review the images.

What is your impression, what is the differential diagnosis, and (if you would biopsy) what technique would you use?

Update:

These are the results from the pathology report. What do you think now? How would you treat further?

– Prof David Wilkinson

We encourage you to participate in the case discussions and sumit your own clinical images and questions, so we can all learn together.