Case report: percutaneous nephrolithotomy for a stone on a Hem-o-lok clip.

A patient was referred to our department for management of a renal pelvis "stone." During percutaneous nephrolithotomy, the stone was discovered to have formed around a Hem-o-lok clip, retained from a previous surgical procedure. As with other surgical foreign bodies, the Hem-o-lok acts as a nidus for stone formation if in prolonged contact with urine. It is radiolucent and therefore crucial to apply with caution in proximity to the urinary tract.