Bowen's disease of the nail.

We present a case of Bowen's disease of the nail bed in a 60-year-old male. This case should remind us to biopsy any chronic lesion of the nail in order to reduce the delay in diagnosis. Indeed Bowen's disease of the nail unit often presents as a clinically misleading 'benign' lesion. Early diagnosis is important as this precancerous lesion appears to have a more aggressive behavior when it affects the nail unit. Bowen's disease of the nail is therefore considered as a squamous cell carcinoma, and both entities are grouped under the term 'epidermoid carcinoma'. Surgical excision is the first treatment option for those tumors without bone involvement. Our patient was treated with Mohs' micrographic surgery which is considered the ideal surgical treatment as it ensures a complete eradication of the tumor in over 90% of the cases but also maximally preserves normal tissue and function. This case illustrates the challenge of Mohs' surgery on the nail unit due to its particular anatomy and histology.