Endocrine Abstracts

Ectopic ACTH is an infrequent cause of Cushing’s syndrome which can be severe in its presentation and needs immediate management to in order to prevent the complications associated with severe hypercortisolism. This case of ectopic ACTH secretion is being reported who presented clinically as Cushing’s syndrome and later diagnosed to have small cell carcinoma of lung. A 62-year-old previously normally fit and well lady presented with 1-month history of feeling unwell, lethargy and weight gain. She was found to have new diagnosis of hypertension (BP 160/110 mm hg), hypokalemia (2.9 mmol/l), metabolic alkalosis (Bicarbonate 30 mmol/land PH 7.50) and mild Cushingoid facies (Fascial plethora, mild thinning of skin and bruises over legs and proximal myopathy). She had no past medical history and was not on any regular medications or steroids. She was a smoker but had no history of cough, hemoptysis, weight loss and chest pain. She had further investigations for relatively acute presentation of Cushing’s syndrome. Her Overnight dexamethasone and low dose dexamethasone suppression tests revealed unsuppressed cortisol. Her ACTH levels were markedly raised. Radiograph of chest revealed left hilar mass which was followed by CT scan chest abdomen and pelvis which revealed left hilar lymphadenopathy and bilateral adrenal hyperplasia. Cortisol day curve showed blunted response. She also had aldosterone renin ratio, plasma metanephrines and MRI pituitary done which were normal. Her Blood glucose and HBA1c were normal. She was managed with IV potassium chloride infusion, anti-hypertensive and potassium sparing diuretics and heparin for prophylaxis. She was subsequently referred to tertiary care hospital for management. She was also started on metyrapone for high burden of cortisol. She had PET Ct scan and EUS guided biopsy of hilar lymph node confirmed small cell carcinoma of lung. She was discussed in oncology MDT and was started on chemotherapy and radiotherapy for lung cancer. Ectopic ACTH related Cushing’s syndrome though rare; however, it should be taken as endocrine emergency as it is usually associated with severe complications of hypercortisolism. It should be urgently evaluated with diagnostic tests for Cushing’s and to localize the ectopic source of ACTH secretion. The strategies to manage these cases are the treatment of source of ACTH and to manage Hypercortisolism and the complications associated with it, including hypertension, hypokalemia, thromboembolic prevention, and prevention of opportunistic infections especially P. Jirovecii. Furthermore, these patients should be managed under multidisciplinary settings.