Endocrine Abstracts

Introduction: A 77-year-old man with glipizide treated type 2 diabetes presented acutely unwell, with weakness, intermittent breathlessness, and poor glycaemic control (previously well control with HBA1c of 42 mmol/mol). Initial assessment showed body weight of 74.5 kg, mild leg oedema, blood pressure of 190/100 mmHg, expiratory wheeze, oxygen saturation 91% and PO₂ 7.8 mmHg on air. Chest XR showed chronic right lower lobe shadowing and a bulky hilum. His plasma glucose was 22.4 mmol/l, potassium 2.4 mmol/l, and sodium of 145 mmol/l. He was treated for heart failure, started on insulin therapy and triaged to endocrinology for hyperglycaemia. Hypokalaemia was refractory to potassium infusion. Further investigations and management: echocardiogram was normal. CT confirmed 5 cm hilar mass with mediastinal lymphadenopathy, small bilateral pleural effusion, consistent with bronchial carcinoma and potential metastasis to both adrenals. Despite lack of Cushing’s feature, Ectopic ACTH secretion was suspected. Urgent random serum Cortisol at 1700 h was very high at 5294 nmol/l with high plasma ACTH of 249 ng/l (normal <50), 24 h Urinary Free Cortisol level was massive at 29 211 nmol/24 h (normal 50–300). He deteriorated within 48 h with significant fluid retention, 5.5 kg weight gain and pleural effusion requiring chest drain. Subsequent confirmatory test for Cushing’s syndrome was deemed unnecessary. He was started on Metyrapone with dose actively up-titrated (1 g tds in 12 days) against the mean serum cortisol day series achieving mean cortisol of 980 nmol/l. spironolactone therapy initiated. He responded well, features of mineralocorticoid excess largely resolved (6 kg weight loss) and able to undergo bronchoscopy confirming small cell bronchial carcinoma.

Discussion: Rapidly progressing ACTH secreting bronchial tumour will not present with typical feature of Cushing. High index of suspicion of such a potential diagnosis is crucial. Bulky adrenals in this case were likely ACTH driven not metastasis (altering the staging). Metyrapone remained the first line of therapy improving metabolic changes.