The secret of the phantom stone: a case report.

A 50-year old man, who has a history of allergies to i.v. contrast and NSAID, was presented with right renal colic. He was treated with regular opiate injections. Plain abdominal X ray showed a 1 cm opacity at the level of L2 but spiral CT failed to locate the urinary calculus. Abdominal examination revealed a small piece of metal implanted in the subcutaneous anterior abdominal wall which was also subsequently identified on CT scanning. When the opiate treatment was withdrawn, the patient absconded.