Endocrine Abstracts

We report the case of a 36 years old female, with personal history of breast cancer, treated with neoadjuvant chemotherapy, breast sectorectomy and then chemotherapy and radiation therapy 2 years ago. She was continuously monitored by her oncologist, disease free for over a year, with recent CT scan that showed no particular lessions suggestive for secondary disease. Meanwhile, she got pregnant and delivered at term a healthy baby. She was admitted 3 months postpartum with intense headache, weight loss, fatigability and low blood pressure. She mentioned hydric intake of aproximate 6 l/day and similiar diuresis during pregnancy. No visual field defects were found at the neurological examination. The initial blood tests revealed panhypopituitarism and central diabetes insipidus and adequate substitution was started. Her blood pressure normalized, but headache persisted without response to pain medication. The magnetic resonance imaging was suggestive for pituitary metastasis and cytologic evaluation of CSF obtained by lumbar puncture was inconclusive. Transsphenoidal surgery was performed and histopatologic exam confirmed a metastatic carcinoma.

Discussion: Although rare, metastatic pituitary spread should always be taken into consideration in a patient with personal history of malignancies and signs and symptoms suggestive of pituitary involvement. Breast cancer is the most likely source of pituitary metastasis in women, while in men lung cancer is usually encountered. Hematogenous tumor spread explains why neurohypophysis is first affected, with early development of polyuria-polydipsia syndrome and diabetes insipidus that precedes anterior pituitary deficiencies. Once diagnosis is made, treatment is difficult and implies correct substitution of hypopituitarism, surgical removal of pituitary lesion, systemic chemotherapy and radiation therapy.

Conclusion: Pituitary metastasis is a rare cause of hypopituitarism and diabetes insipidus associated with a poor prognosis and a median survival rate after diagnosis of 10 months.