Case report: A case series report: recurrent urolithiasis as a risk factor for upper tract urothelial carcinoma

Urothelial carcinoma of the bladder (UBC) and upper tract urothelial carcinoma (UTUC) are distinct malignancies with differing prognoses and molecular characteristics despite their shared histological origin. Emerging evidence suggests that chronic inflammation, often driven by specific carcinogenic exposures, plays a critical role in tumour development. While the oncogenic role of various chemical agents in UTUC is well established, the potential contribution of recurrent urolithiasis remains underappreciated and insufficiently studied. Given the frequent observation of inflammatory polyps surrounding upper tract calculi, further investigation into this association is warranted.

This case series reports on three patients with UTUC in the context of recurrent urolithiasis. Case 1 involves a 53-year-old male patient with a history of repeated ureteric stones and inflammatory polyps who was later diagnosed with low-grade invasive urothelial carcinoma. Case 2 describes a 46-year-old female patient with bilateral renal calculi who developed high-grade invasive UTUC following long-standing calculus disease. Case 3 is a 57-year-old male patient who had recently ingested herbal medicine containing aristolochic acid and was found to have high-grade UTUC, with concurrent urolithiasis potentially contributing to carcinogenesis. In each instance, urothelial carcinoma was initially concealed by polypoid lesions surrounding impacted stones, highlighting the associated diagnostic challenges.

This case series underscores the potential oncogenic role of chronic inflammation induced by recurrent upper urinary tract calculi. Persistent stone-related mucosal injury may contribute to UTUC pathogenesis. Clinicians should maintain a high index of suspicion and perform targeted biopsies of polypoid lesions encountered during the endoscopic management of urolithiasis. Enhanced awareness may facilitate earlier detection and intervention, particularly in patients with recurrent calculus disease.