Case Report: Hydronephrosis and nephrogenic adenoma secondary to Stevens-Johnson syndrome.

Introduction: Stevens-Johnson syndrome is a rare, severe cutaneous adverse reaction. There is a lack of literature reporting the complications of the bladder and ureter caused by Stevens-Johnson syndrome. In this case, we describe a 10-year-old boy with hydronephrosis and nephrogenic adenoma secondary to Stevens-Johnson syndrome. Case description: A boy was admitted to our hospital after a CT scan revealed bilateral hydronephrosis. He had been diagnosed with Stevens-Johnson syndrome earlier. Ureteroscopy and bilateral retrograde ureteral stenting were performed. After the guidewires were introduced, a mass of mucosal debris gushed from the ureteral orifices. Biopsy findings of the mucosal lesions were consistent with nephrogenic adenoma. Two months later, ultrasonography revealed worsening hydronephrosis. The double-J stents were removed. Follow-up ultrasonography showed an improvement in the hydronephrosis. Conclusion: Stevens-Johnson syndrome is a life-threatening mucocutaneous disorder. Ureteral obstruction and hydronephrosis can be caused by mucosal debris in patients with Stevens-Johnson syndrome, which may contribute to and exacerbate renal dysfunction. Nephrogenic adenoma can occur to patient with Stevens-Johnson syndrome as a result of the proliferation of implanted renal tubular cells. Routine ultrasonography should be conducted to monitor the urinary system.