Disorders of body fluids, notably central diabetes insipidus (CDI) and the syndrome of inappropriate antidiuretic hormone secretion (SIADH), are relatively uncommon as a presenting symptom of sellar and suprasellar masses, but quite common following surgical resection of such lesions. It therefore behooves clinicians treating such patients to have a good understanding of the pathophysiology, the differential diagnosis and the management of these disorders. This review discusses some general issues concerning the pathogenesis, differential diagnosis, clinical manifestations and therapy of hyperosmolar and hypoosmolar syndromes, including CDI and SIADH, and then more specifically addresses the evaluation and treatment of pre- and postoperative disorders of water metabolism in patients with pituitary adenomas. PMID: 12675509 [PubMed – indexed for MEDLINE