Silent but Severe: A Case Report of a Large Retroperitoneal Hematoma Following Routine Intradetrusor Botulinum Toxin...

Intravesical botulinum toxin A injections are an established and generally well-tolerated treatment for an overactive bladder. Major complications are uncommon. We report a rare case of a substantial retroperitoneal hematoma following routine intradetrusor botulinum toxin administration. A 53-year-old female with a diagnosis of multiple sclerosis was treated at the urology outpatient clinic for neurogenic bladder symptoms. Four days after the injections, she presented to the emergency department with lower abdomen pain, hematuria, urinary retention, and a visible hematoma around the umbilicus (Cullen's sign). Her hemoglobin level had decreased from 123 g/L to 107 g/L. A CT scan revealed a large pelvic retroperitoneal hematoma measuring 11 × 5 × 5 cm, attributed to the injections. She was managed conservatively. A follow-up CT scan two months later demonstrated a reduction in the size of the hematoma.