Primary carcinoma of the nail bed is a relatively rare tumor. Four additional cases of this type of tumor are reported. The presenting symptoms are usually paronychia, ingrown nail, nail separation, nail deformity, pyogenic granulomalike lesion, pain or bleeding. Delay in diagnosis is frequently prolonged. While these tumors are not usually aggressive and while local removal is usually adequate, one should keep in mind the possibility that metastasis or invasion of the adjacent phalanx or joint can occur.
Nelson LM, Hamilton CF. Primary Carcinoma of the Nail Bed. Arch Dermatol. 1970;101(1):63-67. doi:10.1001/archderm.1970.04000010065011