Numerous melanocytic nevi and lentigines
This question has no specific answer, but was meant to elicit a specific strategy for evaluating and managing patients like this. The patient has a mix of sunburn lentigines, wildly dysplastic nevi and at least one or two possible melanomas. So, friends, how do you deal with someone like this who just walks into your office?
The most important part of your game plan is to win this person over, so he trusts you to monitor him, optimally for the rest of his life. These lesions are guaranteed to change over time, and your job is to pick them off when they start to get too far down the path toward malignancy. Some of you use dermatoscopes, which are a great tool, but others rely on the naked eye and biopsy those spots which stand out.
I do not use a dermatoscope. It is a personal preference, and based on having to remove many melanomas which had been evaluated previously by dermatoscopy and found to be non-malignant. That being said, I do believe dermatoscopes can at times set your mind at ease about some of the lesions you encounter in the course of a busy day. So, if you like them, don't let your naked eye be trumped by your dermatoscope, still biopsy the outliers that don't fit with the rest of the lesions.
The ones I would DEFINITELY biopsy on this guy are the one in the left scapular area and the one on the right upper back with the hyperpigmented poles. After biopsying those, I would ask him to come back in three months, and keep the close follow ups going until I had biopsied all of the crazy lesions on his back. I would not feel compelled to biopsy any of his sunburn lentigines. He should get at the very minimum evaluations every six months.
Since this was such a difficult (can't see the lesions up close) and ambiguous question, I gave you credit for a sharp critical evaluation of the numerous lesions, with a game plan to biopsy the most abnormal ones.