Rare case with metastatic involvement of hypothalamo-pituitary and pineal body presenting as hypopituitarism and diabetes insipidus.

An unusual case with metastatic spread of a small oat cell lung carcinoma to the hypothalamo-pituitary region and pineal body presenting as pituitary insufficiency is reported. Computed tomographic scan revealed an isodense mass in the hypothalamo-pituitary region and pineal body that was strongly enhanced by contrast medium. Magnetic resonance imaging demonstrated a downward displacement of the posterior lobe of the pituitary by the hypothalamo-pituitary mass. Dynamic assessment of hypothalamo-pituitary function showed hypopituitarism and diabetes insipidus; partial recovery was observed with the improvement in the carcinoma by chemotherapy. The brain was subsequently irradiated. The patient survived 10 months.