Pituitary Metastasis: Lung Cancer Presenting as Bitemporal Hemianopsia with Diabetes Insipidus and Anterior Pituitary Deficiency

Symptoms and signs of pituitary disease are rarely the first manifestations of malignancy originating in another organ. We present a case which exemplifies the key points that suggest a diagnosis of metastatic pituitary disease. Our patient's diagnosis was adenocarcinoma of the lung with a metastasis to the intrasellar and suprasellar regions, which caused diabetes insipidus, anterior pituitary deficiency, and visual field defects. The metastasis had a dumbbell appearance and extended from the sella turcica into the suprasellar region. Diabetes insipidus was the initial clinical manifestation of lung cancer in this patient. A metastasis to the pituitary should be suspected if diabetes insipidus is the initial manifestation of an intrasellar mass.