Hi there!
With the description possibility of melanoma and basal cell carcinoma would need to be ruled out. We would probably have to wait till the final biopsy report. After a definite diagnosis is made, it can be managed accordingly.
Hope this is helpful.
Take care!
A second opinion should not take 3 weeks long. You might want to call the pathology department directly yourself to find out the most current findings. What's the size of your son's lesion? What kind of biopsy was performed?