[A case of bladder calculus due to a ruptured balloon fragment of a Foley catheter].

I report a case of bladder calculus developing on a ruptured balloon fragment of the Foley catheter as the nidus. A 65-year-old man suffering from cerebral infarction had been managed with an indwelling urethral Foley catheter for one month. Since the balloon could no longer be deflated, the Foley catheter was removed after rupturing the balloon by overinflation. Four months later, a 3-cm bladder calculus was detected on the plain abdominal roentgenogram. Transurethral cystolitholapaxy revealed a ruptured balloon fragment buried in the core of the calculus. Urine culture was positive for Proteus mirabilis and the stone composition was struvite.