Metastatic Esophageal Adenocarcinoma to the Urinary Bladder During Immunotherapy: A Rare Case Report

Metastatic Esophageal adenocarcinoma to the urinary bladder is extremely rare, with only ten cases reported worldwide. We present a case of a 73-year-old male with a history of esophageal adenocarcinoma treated with neoadjuvant chemoradiation therapy and esophagectomy. Nine months into adjuvant Nivolumab, he developed lower urinary tract symptoms and bilateral hydronephrosis. Cystoscopy revealed diffuse erythematous bladder mucosa without papillary lesions. Biopsies obtained during transurethral resection of the bladder tumor (TURBT) demonstrated invasive adenocarcinoma of the bladder, consistent with metastatic esophageal adenocarcinoma. An additional explorative laparoscopy showed peritoneal nodules consistent with metastatic spread. Systemic therapy was changed from Nivolumab to FOLFOX. After eight cycles of FOLFOX, the patient ultimately developed disease progression with lung metastases and expired six months after TURBT. To the best of our knowledge, this is the first reported case of esophageal adenocarcinoma metastasizing to the urinary bladder during adjuvant immunotherapy.