Ectopic Adrenocorticotropic Hormone Syndrome in a Patient Diagnosed With Lung Adenocarcinoma and Hospitalized Due to Diabetic Ketonuria: A Case Report.

We report a 70-year-old man admitted with pneumonia and diabetic ketonuria without acidosis, in whom EAS secondary to a poorly differentiated lung adenocarcinoma was diagnosed.

Key biochemical findings were a markedly elevated 8 a.m. plasma adrenocorticotropic hormone (149.3 pg/mL), grossly elevated serum cortisol (54.94 μ g/dL) with loss of diurnal rhythm, elevated 24-h urinary free cortisol, and failure of cortisol suppression after both low- and high-dose dexamethasone, with a normal pituitary MRI-a profile consistent with an ectopic adrenocorticotropic hormone source.