ABSTRACT
The metastatic tumor occurs in about 6% to 20% of all cases with central diabetes insipidus. Many kinds of cancers such as breast, lung, colon, prostate, leukemia, and lymphoma can metastasize to the pituitary and its stalk. Primary adenoid cystic carcinoma arising in the bronchus is an uncommon disease. It is histologically and ultrastructurally identical to salivary gland adenoid cystic tumor and is regarded as a slowly growing, low graded-malignancy. This is a case report of a 52-year-old woman with diabetes insipidus caused by a pituitary tumor that might have been associated with adenoid cystic carcinoma arising in the bronchus. The patient was diagnosed by water deprivation test, chest CT scan, bronchoscopic biopsy, and brain MRI scan. The water deprivation test showed the patient had central diabetes insipidus, while chest CT scan revealed a lung mass lesion with distal right intermediate bronchial obstruction. The primary malignancy was confirmed by bronchoscopic biopsy. Finally, we confirmed that the patient had a 7mm-sized mass in the posterior pituitary gland and a thickened stalk by brain MRI scan.