Spontaneous Formation and Resolution of a Large Steinstrasse Without Renal Parenchymal Loss: A Case Report

AbstractAim: We present a case of large-volume ureteral steinstrasse that formed and resolved spontaneously without any medical expulsive therapy (MET) or surgical intervention.Case: A 36-year-old male patient presented with left flank pain. Non-contrast computed tomography revealed high-density calculi obstructing the left upper ureter, with a total stone burden of 4.5 cm, accompanied by grade 3 hydronephrosis. The patient declined the recommended endoscopic surgery. At the 13-month follow-up, multiple stones with a total length of 5.1 cm were observed in the distal ureter. Within two weeks, four stones (8.4, 7.3, 6.6, and 4.7 mm) passed spontaneously; the remaining large stone (24×11 mm), which became impacted in the prostatic urethra, was managed by endoscopic cystolithotripsy. Throughout follow-up, renal function tests remained within normal limits, and no significant loss of renal parenchyma was detected.Conclusions: Large ureteral steinstrasse may pass spontaneously without urological intervention or MET. Keywords: ureteral calculi; steinstrasse; spontaneous passage; hydronephrosis