An unusual phaeochromocytoma crisis presenting with profound hypoglycaemia and subsequent hypertension
Katherine Davis1, Bernard Khoo1, William M Drake1, Ashley B Grossman2 & Sarah Frankton1
A 47 year old Macedonian Personal Trainer presented with 4 days of vomiting, abdominal pain and profuse sweating. He admitted abusing anabolic steroids 20 years previously but never insulin. The presenting capillary blood glucose (CBG) was 1.7 mmol/L, blood pressure (BP) 182/106 mmHg, pulse 62 bpm. On examination, he was sweaty, pale and cold. Blood was drawn for measurement of insulin, C-peptide, glucose, cortisol and thyroid function tests. He was treated with 50% dextrose and 100 mg i.m.hydrocortisone 6 hourly. The CBG rose to 7.1 mmol/L and BP dropped to 115/90 mmHg. The initial differential diagnosis was hypoglycaemia secondary to insulin abuse, hypoadrenalism or insulinoma, the transient hypertension being considered a consequence of sympathetic stimulation.
He remained symptomatically well overnight with a CBG of 1014 mmol/L. Next morning he complained of nausea and abdominal pain. The BP had risen to 203/127, when he was reviewed and given 10 mg i.m. metoclopramide. Shortly afterwards, he developed acute pulmonary oedema and had become hypoglycaemic again. A phaeochromocytoma crisis was suspected and α-adrenoceptor blockade with i.v. phenoxybenzamine advised. However, the patient deteriorated and died on the ITU within 2 hours.
The following blood test results were received post-mortem: cortisol 1202 nmol/L, plasma glucose 1.8 mmol/L, insulin 25.2 mU/L, C-peptide 1174 pmol/L, indicating inappropriate endogenous insulin secretion; troponin T 3.4 μg/L and thyroid function was normal. Post mortem examination confirmed a phaeochromocytoma in the left adrenal, with haemorrhage within the head of pancreas, but no evidence of a pancreatic tumour nor of myocardial infarction.
This is an unusual case of a phaeochromocytoma crisis presenting with hypoglycaemia and only later with hypertension. The tumour did not stain for insulin and the mechanism of the hypoglycaemia remains unclear. Hypotheses include a β-adrenoceptor-mediated release of insulin from the pancreas, release of insulin from damaged pancreatic tissue, or co-secretion of incretins by the tumour.