Endocrine Abstracts

Introduction: The most common cause of diabetes insipidus is idiopathic. However, it may be also seen after metastasis to hypothalamic–pituitary region.

Case: Fifty year old female patient with breast cancer was referred to our clinic with complaints of polyuria and polydipsia. Two years ago, she had diagnosed and after surgery, she has taken three cycles of cyclophosphamide+adriamycin+5-flurourasil than three cycles dosetaxel and finally seventeen cycles herceptin treatment. PET-CT was normal at March 2013, last chemotherapeutic treatment was given 2 months ago before contact us. In the evaluations, the patient’s daily urine volume was found to be ~10–12 l. On physical examination revealed no pathological findings. The patient was hospitalized with a preliminary diagnosis of diabetes insipidus. Water deprivation test revealed central diabetes insipidus. We started desmopressin therapy. After the therapy complaints of polyuria and polydipsia disappeared. Serum osmolarity, serum sodium and urine osmolality levels returned to normal. The nodular lesions that contrasted less than parenchyma in each half of pituitary gland were detected in pituitary MRI and were compatible with metastases. Located in the left hypothalamic–chiasmatic region 3 mm lesion that compatible with metastasis was detected in brain MRI and also multiple metastatic lesions were detected in both cerebral hemispheres. Patient was referred to the medical oncology department.

Conclusion: When investigating the causes of diabetes insipidus, medical history and clinical evaluation is important, and rare causes should be considered. The metastatic tumors of hypothalamic and pituitary region should be noted in a cancer patient.