1184 Bladder Nephrogenic Adenoma Occurred After Repeated IntravesicalOnabotulinumtoxinA (Botox®) Injection for Refractory Overactive

Background This study explores a potential long-term complication of intravesical OnabotulinumtoxinA (Botox®) injections, a prevalent treatment for refractory Idiopathic Overactive Bladder (IOAB). An 83-year-old female, receiving Botox® since 2016, developed bladder superficial villous lesions during the fourth injection, later confirmed as nephrogenic adenoma. While short-term Botox® safety is well-documented, its extended effects remain understudied. Rat models indicate increased urothelial proliferation post-Botox®, and human studies reveal inflammatory changes in bladder urothelium. This case raises concerns about potential irreversible bladder histological changes linked to Botox®. Discussion Nephrogenic adenoma, a rare bladder metaplasia linked to chronic inflammatory states, presents clinical signs resembling urothelial carcinoma. The study reports the first case of nephrogenic adenoma following repeated intravesical Botox® injections, possibly related to urothelial bladder inflammation. Rat models and human studies suggest risks of increased urothelial proliferation and inflammatory changes post-Botox®. This case emphasizes the need for comprehensive longitudinal studies to confirm the prevalence of pathological changes associated with repeated intravesical Botox® injections. In conclusion, the rarity of nephrogenic adenoma in this context underscores the importance of continuous research into the long-term safety of widely used intravesical Botox® injections for overactive bladder treatment. Vigilant monitoring and extended follow-up periods are essential to understand potential adverse effects and ensure the sustained safety of this therapeutic approach.