Hypoglycaemia, phaeochromocytoma and features of acromegaly: a unifying diagnosis?

Abstract

A 53-year-old school teacher was admitted to hospital for investigation of recurrent episodes of spontaneous hypoglycaemia after presenting to the emergency services with loss of consciousness and capillary blood glucose of 1.4 mmol/l. Past medical history was otherwise unremarkable, except for a 10-year history of problematic sweating. This had been treated by her general practitioner with various preparations of hormone replacement therapy (HRT) with little success. However, her symptoms had worsened over the preceding 3 months, associated with mild frontal headaches, but with no palpitations, flushing or pallor. She had also recently been found to be hypertensive and had noticed a change in her facial appearance, associated with increased shoe size, and an inability to wear her rings. Her hair had also recently become curly, having previously always been straight. Accordingly, her doctor had referred her to the endocrinology outpatient clinic for assessment of possible growth hormone excess, but she was unfortunately admitted with hypoglycaemia prior to her consultation. She drank only moderate amounts of alcohol, and had no access to oral antidiabetic agents or insulin. Current medication included HRT, lisinopril, omeprazole and simple analgesics only. There was no family history of endocrine disease. Examination revealed coarsening of facial features, especially the lips and nose, and multiple skin tags were present over the neck and upper back. Blood pressure was mildly elevated at 148/84 mmHg on admission, with no postural drop. There was no skin pigmentation and visual fields were normal to confrontation. Initial investigations including urea and electrolytes, calcium, full blood count and liver function tests were normal except for a raised alkaline phosphatase level of 120 U/l (normal range [NR]: 20–80). An oral glucose tolerance test was planned to assess for suppression of growth hormone, but this was not feasible due to frequent episodes of severe hypoglycaemia. However, insulin-like growth …