I went for my biopsy yesterday.
The nail was taken completely taken off and a biopsy was done centrally and vertically, in the area where the dark line was showing on the nail and a came out with four stitches. Local injections definitely not nice, but procedure beyond that painless. Since the aenesthetic wore off the thumb is surprisingly painful and I am taking the pain meds prescribed. I am sure this will go in time, but at the moment it is quite restricting my activities, especially gardening.
I will take around 3 weeks for the histology to come back so will try and park it and get on with life.
I will let you know when I hear more.
Thanks for all the supportive messages.