Different benign and malignant tumors may arise in the nails, with features depending on the type of tumor and on its localization in the nail apparatus. Signs of nail tumors may be due to the presence of a mass and to the damage to the nail components. Subjective symptoms may or may not be present. Some tumors produce nail signs due to the strict anatomical closeness, as occurs in subungual exostoses. The proximal nail fold is a typical localization of digital myxoid cysts, which arise from the distal interphalangeal joint capsule. The presence of glomus bodies in the nail bed connective tissue makes it a site of onset of glomus tumor, a benign neoplasm arising from glomus cells. Other tumors are exclusive of the nails, as in the case of onychomatricoma, which arises from the connective tissue and the epithelium of the nail matrix. Melanocyte tumors such as nevi and melanoma may arise from nail matrix melanocytes and produce brown to black nail pigmentation. In these cases, the anatomical structure of the nail makes it difficult to use dermoscopy to distinguish between benign and malignant lesions. Twenty percent of nail melanomas are amelanotic, and differential diagnosis with squamous cell carcinoma and pyogenic granuloma may be clinically impossible.