Squamous-Cell Carcinoma of the Nail Bed
A healthy 61-year-old woman presented to the clinic with a 3-year history of a nail deformity accompanied by an indolent ulcer on the left thumb. There was no clear history of trauma or previous wart. The lesion had been diagnosed as paronychia and treated several times with incision and antibiotic therapy. Physical examination revealed an irregular, pigmented, ulcerated lesion on the left thumb nail bed, distal to a yellowish broken nail. The results of a mycologic evaluation were negative. An incisional biopsy was performed, and histopathological examination of the biopsy specimen revealed moderately differentiated squamous-cell carcinoma. Chest radiography and whole-body technetium-99m bone scanning did not reveal any evidence of metastases. The lesion was surgically excised. Squamous-cell carcinoma of the nail bed is rare and often simulates other, benign conditions, such as psoriasis, verruca vulgaris, paronychia, and onychomycosis. Therefore, its diagnosis can easily be missed or delayed.
