Nephrolithiasis in transplanted kidneys is rare but can lead to serious complications. Diagnosis is often delayed due to graft denervation, and treatment is complicated by the kidney’s heterotopic location. We report a case of a renal allograft stone with progressive enlargement, ultimately leading to urosepsis and requiring staged percutaneous nephrolithotomy (PCNL).

A 72-year-old woman, who received a kidney transplant in 1996, had been known to harbor a renal stone in the graft for over 16 years. Despite serial imaging showing progressive enlargement of the stone and recurrent urinary symptoms, she repeatedly declined surgical intervention. By April 2024, she presented with poor appetite and turbid, gray-colored urine. She was diagnosed with urosepsis and obstructive uropathy. CT imaging revealed a massive staghorn calculus occupying the majority of the transplanted kidney, measuring around 5 cm in its largest dimension, with associated hydronephrosis—representing a severely neglected stone burden. The patient underwent three sessions of staged percutaneous nephrolithotomy (PCNL) on May 28, June 3, and July 15. The first procedure revealed extensive stone debris embedded within the graft; the second successfully removed a large staghorn stone accompanied by clots. During the third procedure, residual fragment were removed. Stone analysis confirmed a composition of calcium oxalate and apatite. Her postoperative course was uneventful, with stable renal drainage and gradual improvement. She was discharged in good condition on July 24.

Management of nephrolithiasis in graft kidneys depends on stone size, location, and anatomy. While ESWL and ureteroscopy are less invasive, their effectiveness may be limited by altered urinary tract anatomy. PCNL offers a higher stone-free rate, especially for stones >15 mm, though it poses technical challenges in transplant patients. In this case, staged PCNL allowed complete stone removal with minimal morbidity. This highlights the safety and efficacy of PCNL for large or complex graft stones when performed with proper planning and technique.

Renal stones in transplanted kidneys require early detection and timely treatment. Staged PCNL was effective and safe in this patient with a large staghorn calculus. Regular follow-up and appropriate surgical intervention are key to preserving graft function and preventing complications.