Endocrine Abstracts

A 67-year-old lady presented with hypoglycaemic coma, treated with dextrose infusion. Previously she had a 3-month history of weight gain with increasingly frequent episodes of shaking and blurred vision, particularly at night, relieved by food.

A 72-hour fast was undertaken. Within 2 h, she became confused. Serum glucose was 1.1 mmol/l with serum insulin 527 pmol/l (0–60 pmol/l), proinsulin 320 pmol/l (0–7 pmol/l) and C-peptide 2991 pmol/l (174–960 pmol/l) confirming the diagnosis of insulinoma.

Abdominal computed tomographic (CT) scan identified a 3.0×4.0-cm mass in the tail of the pancreas and multiple ill-defined masses in the liver suggestive of metastases. Intra-arterial calcium stimulation with venous sampling saw insulin levels rise five-fold and two-fold in the right and left hepatic arteries respectively. Octreotide scan demonstrated multiple areas of increased tracer activity throughout the right and left lobes of the liver.

Intravenous 20% dextrose was administered continuously to maintain blood glucose levels and diazoxide was started.

Hepatic arterial embolisation with poly vinyl alcohol particles was performed on 2 occasions, and successfully reduced circulating insulin levels to 29 pmol/l. However symptoms recurred after 4 weeks on both occasions. The patient was re-admitted and CT scan revealed that the liver metastases had increased in size, index lesion increasing from 4.8 to 6.0 cm. 20% dextrose, octreotide and prednisolone were restarted. Unfortunately the patient could not tolerate diazoxide.

Currently the patient is an in-patient, undergoing chemotherapy with streptozocin and capecitabine. Surveillance CT abdomen shows stable hepatic disease. In order to control both tumour growth and hypoglycaemia she has been referred for 90Yttrium-DOTATOC therapy.

This case has been complicated by extreme hyperinsulinaemia resulting in persistent hypoglycaemia which remains difficult to control. We hope that chemotherapy together with 90Yttrium-DOTATOC will enable the patient to be discharged home, withdraw dextrose infusion and have an improved quality of life.