Endocrine Abstracts

81-year-old ex-smoker presented to emergency with transient facial droop, slurring of speech and generalized weakness. He had a background of ischemic heart disease, hypertension, and previous bladder cancer (treated 5 years ago). Examination revealed clinical signs of hypocalcaemia with no cushingoid features. Bloods revealed refractory severe hypokalemia, severe hypocalcaemia with normal phosphate, and metabolic alkalosis requiring High dependency Unit.

Random cortisol done to exclude Cushing’s was greater than 1750 nmol/l (unrecordable upper limit). 24-hour urinary cortisol was 18282 nmol/24 hr (normal 1-124 nmol/24 hours) with no suppression on low dose dexamethasone suppression test (>1750 nmol/l). ACTH was 352 ng/l (normal 0-50 ng/l). PTH was 19.9 pmol/l (normal 1.6-6.9 pmol/l). Vitamin D levels were sufficient. Calcitonin done due to refractory hypocalcaemia was 130 ng/l (normal <10 pg/ml). Renal MRI revealed bilateral adrenal hyperplasia and normal kidneys. Renin: aldosterone ratio done on a sample when potassium was 3.1 mmols/l revealed renin levels of 0.1 nmol/l/hr and aldosterone less than 50 pmol/l. Gut hormone profile was normal except elevated glucagon of 80 pmol/l (normal 0-50 pmol/l). CT Chest/Abdomen revealed a right sided lung 20*14 mm nodule and multiple liver lesions. MRI Pituitary was normal. PET scan did not reveal any further areas of abnormal uptake. Biopsy and immunohistochemical studies of liver lesions showed small cells with nuclear pleomorphism positive for CD56, synaptophysin and chromogranin suggestive of small cell cancer of lung origin. Refractory hypokalemia with a very high ACTH and metabolic alkalosis, is characteristic of ectopic ACTH syndrome. Refractory severe hypocalcemia was further suggestive of rare calcitonin co-secretion. He was planned for inpatient chemotherapy with dexamethasone 4 mg BD. He was stepped down to oral alfacalcidiol 500 ng once a day, calcium lactate gluconate (2.263 g + calcium carbonate 1.75 g), two tablets BD, potassium chloride 600 mg/potassium bicarbonate 400 mg (total potassium 12 mmol) tablets, two tablets TDS with magnesium aspartate (magnesium 10 mmol) BD. Unfortunately, the patient succumbed to COVID/Sepsis. Early initial medical management of ectopic ACTH and early recognition of co-secretory tumors in cases of multiple electrolyte derangements may be helpful in achieving a more positive outcome in future. A multidisciplinary management in liaison with critical care, oncology and endocrine is paramount