A Rare Convergence: Verrucous Squamous Cell Carcinoma Arising From Bowen's Disease in an Uncommon Cutaneous Location.

Verrucous squamous cell carcinoma (VSCC) and Bowen's disease (BD) are neoplasms of squamous cell origin. Bowen's disease is the widely used term for squamous cell carcinoma in situ and primarily involves the skin, whereas VSCC represents a well-differentiated, locally aggressive variant of squamous cell carcinoma. These entities differ in their risk factors, biological behavior, and therapeutic approach. Cutaneous VSCC is typically human papillomavirus-independent (HPV-independent) and often requires wide local excision, while BD is frequently associated with HPV infection, arises on sun-exposed skin, and may respond to non-surgical treatment modalities. We report a rare case of VSCC arising in a background of Bowen's disease over the lower back--an uncommon site for both lesions. The patient underwent wide local excision with Limberg flap reconstruction, and histopathological examination confirmed VSCC with adjacent Bowen's disease. This case highlights the importance of recognizing dual pathology in atypical cutaneous lesions to ensure appropriate surgical planning and management.