Endocrine Abstracts

A 73 years old gentleman with a diagnosis of mesothelioma presented with symptoms typical of hypoglycaemia. Other than the expected abnormal chest signs there were no significant examination findings.

Capillary glucose was unrecordable; lab testing confirmed serum glucose of 0.9 mmol/l. He had no history of diabetes mellitus or any medication that may induce hypoglycaemia. There was a slight rise in CRP and white cell count was elevated. There was no clinical evidence of infection. Routine biochemical tests were normal. Chest X-ray showed extensive left chest shadowing.

Intramuscular glucagon and intravenous dextrose initially improved blood glucose but episodic symptomatic hypoglycaemia continued. Blood glucoses fluctuated between 0.9 and 2 mmol/l. Despite aggressive treatment with dextrose 10% and additional dextrose 50% boluses he continued to have frequent hypoglycaemia.

Having previous treatment with steroids a short synacthen test was requested, which was normal. A recent CT scan showed no adrenal, hepatic or pancreatic lesions.

With no other apparent cause a presumptive diagnosis of non islet cell tumour hypoglycaemia was made. This was confirmed by suppressed insulin (<10 pmol/l) and c-peptide (<94 pmol/l) levels with a high IGF2:IGF1 ratio (19.3).

Chest ultrasound confirmed significant mesothelial tumour with little pleural fluid. He was treated with high dose corticosteroid, diazoxide and octreotide infusion. Severe hypoglycaemia remained problematic necessitating continued glucose infusions. He was unfit for chemotherapy or debulking surgery and deteriorated rapidly before dying 7 days after admission.

Non islet cell tumour hypoglycaemia is a rare paraneoplastic phenomenon. Treatment involves reduction in tumour size by chemotherapy or surgery. Hypoglycaemia can remain significant and resistant to medical management strategies.