Bowen's disease (BD) is the second most common skin cancer worldwide, often linked to sun exposure, arsenic, and immunosuppression. Though rare in pediatrics, it is the third most common pediatric skin cancer, associated with conditions like albinism and immunosuppression. Recent years have seen an increase in Squamous Cell Carcinoma (SCC) cases among children, potentially related to immunosuppression and human papillomavirus (HPV) infection, particularly subtype 16. We present the case of an 11-year-old girl from Mexico City with a five-year history of a slowly growing, asymptomatic, dark-brown plaque on the periungual region of her right hand. Histopathological examination revealed Pigmented Squamous Cell Carcinoma in situ. The lesion was treated with excision, nail apparatus removal, and adjuvant 5% imiquimod cream, followed by skin grafting. This case underscores the importance of considering malignancy in pediatric patients, particularly with atypical presentations in acral sites, and highlights the diagnostic challenges of pigmented SCC.

Keywords: cancer; periungual; squamous cell carcinoma.

© The Author(s) 2025. Published by Oxford University Press.