Endocrine Abstracts

Introduction: Ectopic ACTH production accounts for up to 20 percent of ACTH-dependent Cushing syndrome (CS). Small cell carcinoma and carcinoid of the lung represents half of its cases. These patients lack some of the more obvious clinical features of cortisol excess. Therefore, this can cause a delay in the diagnosis of CS and these patients may be at high risk of life-threatening complications such as infections or thrombosis.

Clinical case: Case of a 70-year-old man, with recent diagnosis of small cell lung cancer was admitted for rapidly progressing hypertension, hypokalemia and severe hyperglycemia. There was no previous medical history of diabetes or hypertension. On physical examination, he did not have typical Cushingoid features; he presented lower extremity edema and high blood pressure reaching 180/120mmHg. At admission, plasma glucose was 336mg/dl, serum potassium 2.6mmol/l, arterial pH 7.54. Cushing syndrome was suspected, and an endocrine evaluation revealed an ACTH-dependent hypercortisolism: cortisol after an overnight 1-mg dexamethasone suppression test 60.6μg/dL and ACTH 175.5ng/l. CRH stimulation test had a borderline result to differentiate the cause. Treatment with metyrapone was considered immediately and readily requested to the hospital pharmacy committee; however, there was a delay in the provision of the drug. He started emergency treatment with potassium supplementation and spironolactone. In order to use somatostatin analogs to treat the ectopic secretion, a 111-In-octreotide scan was performed, that revealed receptors in the left lung and contralateral pleura. Unfortunately, on the tenth hospital day, before any treatment for hypercortisolism was started, the patient’s hospital course was complicated with a nosocomial pneumonia and the patient died.

Conclusion: Patients with ectopic ACTH secretion can be very hard to detect and typically present with a much more rapid progression compared to Cushing disease. Indeed, these patients often represent an endocrine emergency due to the intensity of their hypercortisolism. Worsening hyperglycemia in the presence of hypertension, even without typical Cushing features should prompt further hormonal work-up. To offer the patient the best chance of survival and avoid Cushing’s complications such as severe infections, hypercortisolism must be controlled without delay.