Subungual amelanotic malignant melanoma.
D001706:Biopsy; D006801:Humans; D008297:Male; D008545:Melanoma / Q000473:pathology*; D008875:Middle Aged; D009260:Nail Diseases / Q000473:pathology*; D009262:Nails / Q000473:pathology; D012867:Skin / Q000473:pathology; D013933:Thumb