Multiple-Digit Pigmented Bowen’s Disease Induced by Human Papillomavirus in an Immunocompetent Child

Introduction: Bowen’s disease is a squamous cell carcinoma in situ, the most common malignancy of the nail unit. Presenting more frequently in the fingernails, common risk factors include ionizing radiation, oral exposure to arsenic or pesticides, dyskeratosis congenita, and quite commonly diverse subtypes of HPV. We report the first case of multiple periungual pigmented Bowen’s disease in a pediatric patient. Case Presentation: A healthy 13-year-old boy presented with a 9-month history of a pigmented erythematous patch on the proximal nail fold of his 3rd right finger without associated symptoms. A punch biopsy was taken, and the diagnosis of Bowen’s disease was made. The patient received photodynamic therapy and three cycles of imiquimod without response, and two new lesions appeared on the first and second right fingers. Surgical removal was performed on all lesions. A polymerase chain reaction detected an HPV type 16. Discussion/Conclusion: Multiple periungual Bowen’s disease is rare, with the most frequent risk factors being HPV infection and chronic immunosuppression. Less than 10% of the cases present as longitudinal melanonychia. To date, there are no previous reports of multiple pigmented periungual Bowen’s disease. HPV-induced Bowen’s disease is usually present in adults aged between 22 and 89 years as persistent verrucae. In this case, koilocytosis and the fact that all lesions appeared on the right hand are suggestive of HPV infection.

Introduction: Bowen's disease is a squamous cell carcinoma in situ, the most common malignancy of the nail unit.Presenting more frequently in the fingernails, common risk factors include ionizing radiation, oral exposure to arsenic or pesticides, dyskeratosis congenita, and quite commonly diverse subtypes of HPV.We report the first case of multiple periungual pigmented Bowen's disease in a pediatric patient.Case Presentation: A healthy 13-year-old boy presented with a 9-month history of a pigmented erythematous patch on the proximal nail fold of his 3rd right finger without associated symptoms.A punch biopsy was taken, and the diagnosis of Bowen's disease was made.The patient received photodynamic therapy and three cycles of imiquimod without response, and two new lesions appeared on the first and second right fingers.Surgical removal was performed on all lesions.A polymerase chain reaction detected an HPV type 16.Discussion/Conclusion: Multiple periungual Bowen's disease is rare, with the most frequent risk factors being HPV infection and chronic immunosuppression.Less than 10% of the cases present as longitudinal melanonychia.To date, there are no previous reports of multiple pigmented periungual Bowen's disease.HPVinduced Bowen's disease is usually present in adults aged

Introduction
Bowen's disease is a squamous cell carcinoma in situ, the most common malignancy of the nail unit.Presenting more frequently in the fingernails, clinical features include onycholysis, hyperkeratosis, paronychia, ulceration, nail plate destruction, leukonychia, erythronychia, and longitudinal melanonychia.Common risk factors include ionizing radiation, oral exposure to arsenic or pesticides, dyskeratosis congenita, and quite commonly diverse subtypes of HPV [1].While rare, multiple nonpigmented periungual Bowen's disease and multiple pigmented Bowen's disease elsewhere in the body have been reported.We report the first case of multiple periungual pigmented Bowen's disease in a pediatric patient.

Case Presentation
A healthy 13-year-old boy presented with a 9-month history of a pigmented erythematous patch on the proximal nail fold of his 3rd right finger without associated symptoms (Fig. 1a).A punch biopsy was taken, showing an acanthotic epidermis with atypical keratinocytes, with large, pleomorphic, hyperchromatic nuclei (Fig. 2).With these findings, the diagnosis of Bowen's disease was made.The patient received photodynamic therapy and three cycles of imiquimod without response and developed longitudinal melanonychia over the course of 9 months, besides spread of the initial lesion (Fig. 1b).In the same time lapse, two new lesions appeared on the first and second right fingers (Fig. 3).Removal of the nail unit and skin grafting of the 3rd right finger were performed, and wide excision with secondary intention healing of the lesions of the 1st and 2nd right fingers (proximal nail fold).The biopsy of all lesions showed the same changes, along with koilocytosis.A polymerase chain reaction detected an HPV type 16.During the first clinical examination, concomitant wart lesion was observed in the genital area.The patient has been followed for 6 years with no recurrence.

Discussion
Multiple periungual Bowen's disease is rare, with the most frequent risk factors being HPV infection and chronic immunosuppression [2].Less than 10% of the cases present as longitudinal melanonychia [3].To date, there are no previous reports of multiple pigmented periungual Bowen's disease.Given the lack of treatment guidelines, proposed therapeutic options include imiquimod, photodynamic therapy, wide-margin excision, Mohs surgery, and radiotherapy [3,4].
HPV-induced Bowen's disease is usually present in adults aged between 22 and 89 years as persistent verrucae [5].Several HPV subtypes have been identified, with type Fig. 1. a A pigmented erythematous patch in the proximal nail fold of the right middle finger.b Clinical presentation 20 months after showing lack of improvement and longitudinal melanonychia and nail dystrophy.