輸尿管及膀胱黏液性腺癌引發之嚴重腎及輸尿管積水：罕見病例報告

沈毓明、黃勝賢

彰化基督教醫院泌尿外科

Mucinous Adenocarcinoma in the Ureter and Bladder Leading to Severe Hydronephrosis and Hydroureter: A Rare Case Report

Yu-Ming Shen, Sheng-Hsien Huang

Division of Urology, Department of Surgery, Changhua Christian Hospital

Introduction

Mucinous adenocarcinoma is an uncommon malignancy within the urinary system, with transitional cell carcinoma and squamous cell carcinoma comprising the majority of tumors in the renal pelvis. This cancer type is extremely rare in the ureter and bladder, where most cases of urinary mucinous adenocarcinoma are generally associated with the renal pelvis, often due to chronic inflammation or irritation. The presented case is unique, involving the ureter and bladder instead of the renal pelvis, thus expanding our understanding of potential sites affected by this rare pathology.

Case presentation

A case of a 67-year-old male is presented, with initial symptoms of left-sided flank discomfort. Diagnostic imaging via abdominal computed tomography revealed significant hydronephrosis of the left kidney with parenchymal atrophy and notable ureteral dilatation (Figure 1). Although inpatient evaluation was recommended, the patient opted for outpatient management. After thorough discussion of available treatment options, a percutaneous nephrostomy was established. Subsequent imaging studies conducted one year post-procedure demonstrated persistent severe left-sided hydronephrosis and hydroureter. Additionally, imaging revealed a polypoid mass within the urinary bladder. Surgical intervention was undertaken, comprising transurethral resection of the bladder tumor, excision of the bladder cuff, and left radical nephroureterectomy. Intraoperative findings were significant for an extensive mucus-producing bladder neoplasm adjacent to the left ureteral orifice. Due to suspected local invasion, concurrent segmental ileal resection and anterior sigmoid resection were performed. Histopathological examination confirmed a well-differentiated mucinous adenocarcinoma involving the left ureter and bladder, while the intestinal specimens showed no evidence of malignancy. The postoperative course was uneventful, and the patient was discharged in stable condition. Regular follow-up continues through our outpatient urology service.

Discussion

Mucinous adenocarcinoma of the urinary system, particularly in the renal pelvis, has been sparsely documented, with fewer than 100 cases reported. Its occurrence in the ureter and bladder is exceedingly rare. Histologically, these tumors often resemble mucinous adenocarcinomas from the gastrointestinal tract and may present with nonspecific symptoms such as hematuria, flank pain, or mucus-like discharge. Chronic urological conditions, including calculi and pyonephrosis, are implicated in the development of such tumors through prolonged epithelial irritation and metaplasia. Diagnosis remains challenging, as mucinous adenocarcinomas lack distinctive radiological characteristics, frequently resulting in misdiagnoses like pyonephrosis. Imaging and elevated serum markers (e.g., CEA, CA19-9) may aid diagnosis, though confirmation relies on histopathology, which identifies mucin-secreting cells. Standard treatment involves radical nephroureterectomy, but in cases involving ureter or bladder, more extensive excision may be necessary. Adjuvant therapies, including chemotherapy, show limited efficacy. This case emphasizes the need for awareness of this rare pathology's diverse manifestations in the urinary tract to avoid iatrogenic tumor spread and improve outcomes.