Diabetes insipidus caused by isolated intracranial metatstases in patient with breast cancer

We present a case of late recurrence of breast cancer manifested with diabetes insipidus caused by isolated intracranial metastases. A 57-year-old postmenopausal woman was diagnosed with breast cancer and underwent radical mastectomy, without any adjuvant therapy. Seventeen years later, she presented with polyuria, polydipsia, weight loss, weakness, diffuse bone pain, hoarseness and mild dyspnoea. Cranial CT revealed several dural masses in the frontal, parietal and occipital lobes and along the falx cerebri. The diagnosis of central diabetes insipidus without impairment of anterior pituitary function was based on the clinical symptoms, laboratory tests and imaging findings. The patient was successfully treated with desmopressin acetate and letrozole, and remained alive and ambulating 22 months after initial presentation with diabetes insipidus.