Massive cystine staghorn calculus in a a dominant kidney with poorly functioning contralateral side: a case report and surgical management

Cystine stones are a rare form of urolithiasis, accounting for less than 2% of urinary calculi. Their tendency for rapid growth, recurrence, and resistance to fragmentation makes management challenging, especially in patients with a solitary functional kidney. A 54-year-old man with type 2 diabetes mellitus and a history of bilateral nephrolithotomy presented with severe right flank pain. Computed tomography imaging revealed an 8-cm cystine staghorn calculus occupying the entire right renal pelvis, with additional multiple calculi. Renal scintigraphy showed 76% function in the right kidney and 24% in the left. Open stone surgery was performed, involving adhesiolysis, temporary vascular control, and extraction of 13 stones. The patient recovered well postoperatively, with a stone-free status confirmed on a kidney–ureter–bladder (KUB) X-ray and stable renal function. Open surgery remains a valuable option in managing extensive cystine stone burdens, particularly in complex cases with a dominant kidney and a poorly functioning contralateral side.