Rhabdomyolysis in hyponatremia and paraneoplastic syndrome of inappropriate antidiuresis.

We report a 26-year-old woman admitted to our hospital for generalized tonic seizure. Laboratory investigations revealed severe hyponatremia possibly triggered by vomiting and diarrhea. 24 hours after correction of hyponatremia she developed diffuse myalgias and marked hyperCKemia. Syndrome of inappropriate antidiuresis (SIAD) was suspected as cause of hyponatremia. Abnormal vaginal bleeding prompts gynecological evaluation and a small-cell carcinoma of uterine cervix was detected.