Inverted papilloma of the urinary bladder presenting during pregnancy

A 28-year-old woman at 24 weeks' gestation visited our outpatient clinic complaining of painless hematuria. Ultrasonography showed polypoid mass within the bladder. Cystoscope revealed papillary pedunculated tumor on the anterior wall of the bladder. She underwent TURBT under spinal anesthesia at 25 weeks' gestation. Although weak contraction of the uterus occurred after operation, it was controlled by administration of ritodrine hydrochloride. Histological examination revealed inverted papilloma. She completed her pregnancy and delivered a full-term healthy infant. The recurrence of the tumor was not detected 28 months after the operation. To our knowledge, this is the first case of inverted papilloma during pregnancy.