Diabetes insipidus from metastatic oat cell carcinoma: recovery after brain irradiation.

A hypothalamic metastasis was demonstrated by computed tomography in a 71-year-old patient, with previously unknown small cell lung cancer, who presented with diabetes insipidus and biological signs of hypothyroidism and hypogonadism. Brain irradiation resulted in resolution of polyuria, elevation of thyroid hormones, improvement of pituitary responsiveness to hypothalamic releasing hormones, and complete disappearance of contrast-enhanced suprasellar metastasis.