Ectopic Cushing syndrome in small cell lung cancer: A case report and literature review

Small cell lung cancer (SCLC) is a neuroendocrine tumor with the potential to secrete various peptides or hormones that can lead to paraneoplastic syndromes, such as Ectopic Cushing syndrome (ECS). Because of the aggressive nature of the syndrome and its atypical features, ECS in small‐cell lung cancer is difficult to diagnose and has a poor prognosis. We report a case of a 74‐year‐old male patient who presented with severe hypokalemia, proximal muscle weakness, peripheral edema, metabolic alkalosis, and worsening hyperglycemia. The patient was eventually diagnosed with stage IV primary small‐cell lung cancer and survived three months after diagnosis. We reviewed published articles to determine any new diagnostic techniques or advantages in the treatment regimen.