The diagnosis of a nail tumor is established through a physical examination and dermatoscopic evaluation performed by a dermatologist. Following this initial assessment, the physician can largely determine the presence and type of the nail tumor. In suspicious cases or situations requiring a definitive diagnosis, a nail biopsy (biopsy of the nail and nail bed) is performed. If cancer is strongly suspected, once the diagnosis is confirmed by biopsy, the tumor is surgically removed as soon as possible.