Insulinoma is a rare neuroendocrine tumour of the pancreas, which is usually small, solitary and benign. It may be part of multiple endocrine neoplasia type-1 syndrome. It is characterised by hypoglycaemic episodes as a result of inappropriate secretion of insulin from the pancreatic adenoma cells.
Whipple’s triad is pathognomic of insulinoma, which includes: 1) symptoms of neuroglycopaenia, 2) documented hypoglycaemia (plasma glucose level less than 50 mg/dl) and 3) relief of symptoms (often within 5–10 min) following glucose administration. Documented hyperinsulinism in presence of hypoglycaemia warrants further investigations to confirm the diagnosis. Gold standard for the diagnosis is a 72 h-fasting test, demonstration of Whipple’s triad. The localisation of the tumour is a challenge for the clinicians. Surgical resection is the curative treatment with a high success rate. Intraoperative ultrasound and surgical palpation confirm the site of the tumour. There may be severe hypoglycaemia during surgical handling of the tumour, symptoms of which may be masked when the patient is under anaesthesia. So the main anaesthetic concern is to maintain an optimum plasma glucose level. Glucose infusion and frequent plasma glucose monitoring to maintain glucose level more than 60 mg/dl is found to be helpful.