two tone lesion
This is the sort of lesion which causes concern due to mixed asymmetrical colour. The dermoscopy is helpful.
Dermoscopy reveals many milia like cysts throughout the lesion. Although a few of these cysts may uncommonly be seen in melanomas and other lesions, to see as many as this all the way through a lesion is strongly suggestive of a seborrhoeic wart.
What might worry you is the darker section on the left. This however is a common finding on a seborrhoeic wart. There are no features of a melanocytic lesion (reticular network or globules), many milia like cysts which is good for a seb wart, and going back to the main view, there is a very good ‘stuck on’ edge. This is not the blue grey veil of a melanoma, careful inspection reveals many small hairpin type vessels in tight halos. This is a very good dermoscopic sign for warts, and negates the potentially worrying bluish grey colour. I suppose there might be the risk of a melanoma developing underneath a seb wart, a rare type of collision lesion, but this would be very unlucky. If feeling anxious, remove for histology by deep shave and light cautery, don’t cut out and stitch-more effort, worse scar. When you have dermoscoped a couple of hundred seb warts, you will realise that they are not always uniform in colour. I’m never going to stop saying this-if in doubt, refer. But this IS a benign lesion.
PS another feature often seen in melanoma is linear irregular or dotted vessels. Don’t worry about more sophisticated signs as this, more advanced stuff, but suffice it to say they can’t be seen in this lesion. No signs of mole, melanoma or BCC, not a haemangioma, positive signs of a seb wart. What’s there to worry about?