: We present a case of 79 year old lady who presented to hospital with symptoms of polyuria and polydipsia requiring admission for level 3 care. She reported no bowel symptoms or alcohol usage. Her past medical history showed that she suffered from T2DM, Epilepsy, Asthma, Hypertension and Chronic Kidney disease. Her biochemistry revealed a combination of Hyperglycaemia, Hypokalaemia, Hypomagnesemia, Hypophosphatemia, Hyponatremia and Hypocalcaemia. Her medications revealed no causes of above biochemical abnormality (i-e loop and thiazide diuretics, aminoglycosides, ciclosporin, cisplatin) but her ACE inhibitor was stopped. On exmaination there were no systemic features of Cushingoid habitus. Her blood gas revealed metabolic alkalosis and she was treated with Potassium replacement and Spironolactone with limited improvement in intensive care.
Further advised was sought from the Endocrinology team and her cortisol/ACTH levels were elevated (i-e 3160 (523 μg/dl) and 386 (10 and 60 pg/ml)). It was treated with oral spironolactone. Her Urine revealed a high urine osmolarity with a 24 h urine Na of 326 mmol/l and urine K 268 mmol/l. Low Dose Dexamethasoen Suppression test (LDDST) showed lack of suppression of cortisol (Table 1)
She was initiated on Metyrapone on basis of abnormal DST. Her CT Chest, Abdomen and Pelvis revealed no apparent source of ectopic ACTH but bilaterally enlarged adrenal glands. Unfortunately further imaging and histology was not possible because of multiple epsiodes of sepsis including a HDU admission.
|Cortisol (μg/dl)||ACTH (pg/ml)|
Conclusion: Hypokalemia, Hypomagnesemia, Hypophosphatemia, Hyponatremia and Hypocalcemia as first presentation of Ectopic ACTH production is rare. Other common causes like alcoholism, Cisplatin therapy, Diuretic use etc have been defined in Literature. This case highlights that this rare diagnosis should be considered in similar clinical presentation and early treatment should take priority over complete work up in severe case of Ectopic ACTH presenting with Cushings syndrome. A management plan with high dosage Spironolactone, Metyrapone and Ketaconazole might be advisable as part of the decision making process. There is a need for future studies to improve the evidence base in the similar area.