[Secondary hypopituitarism due to hypothalamic metastasis from small cell lung cancer].

Parasellar and hypothalamic metastases are uncommon. Their principal clinical manifestation is diabetes insipidus. Associated hypopituitarism is very rare. We report the case of a 54-year-old man with small cell lung cancer and hypopituitarism. A brain magnetic resonance imaging scan revealed a mass in the anterior region of the third ventricle with no clear etiology. The patient began chemotherapy treatment and the mass disappeared, which confirmed the diagnosis of secondary hypopituitarism caused by hypothalamic metastasis from small cell lung cancer.