A giant serous papillary cystadenofibroma mimicking a bladder tumor: A diagnostic pitfall

A 54-year-old woman with urinary incontinence and multiple comorbidities was evaluated for a suspected bladder tumor after ultrasonography revealed a posterior bladder wall mass. Cystoscopy showed no intravesical lesion. Further imaging demonstrated a large cystic pelvic mass arising from the left adnexa, causing extrinsic bladder compression without invasion. The patient underwent total hysterectomy with left salpingo-oophorectomy and omentectomy. Histopathology confirmed serous papillary cystadenofibroma. This case highlights that adnexal masses may mimic bladder tumors on imaging, and emphasizes the importance of cystoscopy and cross-sectional imaging for accurate diagnosis and avoidance of unnecessary intervention.