Carcinome basocellulaire de l’appareil unguéal de l’hallux

Background. Basal cell carcinoma is a very common form of skin cancer but its occurrence on the toenail unit is very rare. We report such a case of basal cell carcinoma localized on the proximal nail fold of the right hallux. Case report. A 67-year-old woman had a 7-year history of a non-healing ulcer on the proximal nail fold of the right hallux after antibiotics and treatment of her onychomycosis. Bowen's disease and squamous cell carcinoma were suspected. Histopathologic examination of a biopsy specimen revealed infiltrative basal cell carcinoma. The lesion was surgically excised with a 0.5 cm margin and the defect was repaired by full-thickness skin graft with good functional and cosmetic results. Discussion. Basal cell carcinoma is the most common skin cancer but its localization on fingers, toes and nail units is very rare. Only six cases of basal cell carcinoma on the toe nail unit have been reported to date in the literature. Clinical aspects often mimic benign processes, resulting in misdiagnosis. Treatment requires simple excision or Mohs micrographic surgery. Our case emphasizes the value of biopsy for all nail unit lesions of atypical appearance, course or therapeutic response.