Carcinomatous meningitis associated with ovarian cancer complicated by SIADH.

We experienced a case of carcinomatous meningitis originating from stage IIIc ovarian cancer complicated by syndrome of inappropriate antidiuretic hormone secretion (SIADH). A 51-year-old woman had been treated with multiple chemotherapy regimens after an initial operation for ovarian cancer. During the last chemotherapy regimen, she suffered headache, mood changes and ataxia. After one week, she had a convulsive seizure and lost consciousness. Laboratory studies showed hyponatremia, low serum osmolality, elevated urinary sodium level and urine osmolality. Cranial-enhanced magnetic resonance imaging (MRI) revealed abnormal meningeal enhancement. A lumbar puncture examination revealed that numerous atypical cells were present. Carcinomatous meningitis complicated by SIADH was diagnosed and treatment for hyponatremia and whole brain radiotherapy were performed; however, she died two weeks after the radiation therapy. Clinicians should consider carcinomatous meningitis when there are findings of SIADH.