Small-Cell Lung Cancer Presenting as Diabetes Insipidus and Cushing's Syndrome

Small-cell lung cancer presenting with a combination of cranial diabetes insipidus and Cushing's syndrome secondary to ectopic adrenocorticotropin (ACTH) secretion is very rare and has only been described previously in one case report Our patient was a 49 year old man, in whom the initial presenting features of small-cell lung cancer were cranial diabetes insipidus secondary to pituitary metastases and severe hypokalaemia resulting from ectopic ACTH hormone secretion. This case is a remarkable example of the complex metabolic endocrine manifestations of small-cell lung cancer.