Squamous cell carcinoma of the upper urinary tract revealed by severe infection in a duplicated ureter with Lithiasic ureterocele: A case report and literature review

Introduction: Primary squamous cell carcinoma (SCC) of the upper urinary tract is a rare tumor representing less than 1% of renal neoplasms. It is strongly associated with chronic irritation, particularly related to urinary calculi and recurrent infections. Diagnosis is often delayed, due to a non-specific clinical presentation that may mimic severe infectious conditions. The association of ureteral duplication with a complicated ureterocele is extremely rare.
Case Presentation: We report the case of a 60-year-old patient with no significant medical history who presented with febrile acute left-sided pyelonephritis. Imaging revealed a duplicated left kidney with marked dilation of the upper pole collecting system secondary to a tissue thickening at the ureterovesical junction, suggestive of a complicated lithiasic ureterocele. A multiloculated retroperitoneal abscess extending along the psoas muscle was also identified. Initial management included percutaneous drainage and internal urinary diversion with placement of two double-J stents. Subsequently, a nephroureterectomy with bladder cuff excision was performed. Histopathological examination revealed a well-differentiated squamous cell carcinoma infiltrating the renal parenchyma (pT3NxMx), with vascular emboli and a positive ureteral margin. The clinical course was marked by the rapid development of necrotic mediastinal and retroperitoneal lymphadenopathy suggestive of metastatic progression.
Conclusion: This case highlights the aggressive nature of upper urinary tract squamous cell carcinoma and underscores the importance of considering a malignant etiology in any chronic obstruction complicated by severe infection, particularly in the presence of underlying anatomical abnormalities.