Diabetic Ketoacidosis as the First Manifestation of Ectopic Cushing's Syndrome

Diabetic ketoacidosis is an exceptionally rare initial manifestation of ectopic adrenocorticotropic hormone (ACTH) syndrome. A 42-year-old woman with multiple cardiovascular risk factors was admitted to the emergency room with diabetic ketoacidosis. During stabilization, florid Cushing's syndrome was suspected and confirmed biochemically as ACTH-dependent. Further biochemical and imaging surveys led to the diagnosis of a 25x15 mm nodule in the lingula. Thoracic surgery was performed, and pathology revealed a neuroendocrine tumor positive for ACTH. We reviewed eight additional cases of diabetic ketoacidosis associated with Cushing's syndrome from PubMed. Clinicians should bear in mind this etiology of diabetic ketoacidosis based on clinical signs and younger patients with multiple, age-atypical comorbidities. This would permit the expedited targeted stabilization of Cushing's syndrome and the suitable institution of the diagnostic approach and treatment for this challenging syndrome.