Severe paraneoplastic hypoglycemia secondary to a gastrointestinal stromal tumour masquerading as a stroke.

UNLABELLED: We report the case of a 70-year-old previously healthy female who presented acutely to the Accident and Emergency department with left-sided vasomotor symptoms including reduced muscle tone, weakness upon walking and slurred speech. Physical examination confirmed hemiparesis with VIIth nerve palsy and profound hepatomegaly. A random glucose was low at 1.7 mmol/l, which upon correction resolved her symptoms. In hindsight, the patient recalled having had similar episodes periodically over the past 3 months to which she did not give much attention. While hospitalized, she continued having episodes of symptomatic hypoglycaemia during most nights, requiring treatment with i.v. dextrose and/or glucagon. Blood tests including insulin and C-peptide were invariably suppressed, in correlation with low glucose. A Synacthen stimulation test was normal (Cort (0') 390 nmol/l, Cort (30') 773 nmol/l). A computed tomography scan showed multiple lobulated masses in the abdomen, liver and pelvis. An ultrasound guided biopsy of one of the pelvic masses was performed. Immunohistochemistry supported the diagnosis of a gastrointestinal stromal tumour (GIST) positive for CD34 and CD117. A diagnosis of a non islet cell tumour hypoglycaemia (NICTH) secondary to an IGF2 secreting GIST was confirmed with further biochemical investigations (IGF2=96.5 nmol/l; IGF2:IGF1 ratio 18.9, ULN <10). Treatment with growth hormone resolved the patient's hypoglycaemic symptoms and subsequent targeted therapy with Imatinib was successful in controlling disease progression over an 8-year observation period. LEARNING POINTS: NICTH can be a rare complication of GISTs that may manifest with severe hypoglycaemia and neuroglucopenic symptoms.NICTH can masquerade as other pathologies thus causing diagnostic confusion.Histological confirmation of GIST induced NICTH and exclusion of other conditions causing hypoglycaemia is essential.Mutational analysis of GISTs should be carried out in all cases as it guides treatment decision.Tailored management of hypoglycaemia, in this case using growth hormone and targeted cyto-reductive therapy, minimizes the risk of possible life-threatening complications.

Efficacy of a new needleless insulin delivery system monitoring of blood glucose fluctuations and free insulin levels.

A new insulin delivery system Vitajet has been invented which involves a high-pressure spring and obviates the use of needle injections. To study its efficacy we compared blood glucose fluctuations, integrated glycemia, free insulin and total free insulin concentrations in six insulin-dependent diabetics. After obtaining a steady state of carbohydrate metabolism overnight by feedback control through the artificial endocrine pancreas (AEP) Biostator, the patients received their usual morning and evening doses of insulin by either conventional injection or Vitajet in random order. Blood glucose levels were significantly lower after Vitajet than conventional injections (p less than 0.04) between 10 a.m. and 4 p.m., but the difference disappeared from 4 p.m. onwards. The areas under the curve (AUCs) of glucose fluctuations were lower after Vitajet (28036 +/- 4655 vs 31086 +/- 2310 mg. min% mean +/- SEM, p less than 0.01). AUCs for free insulin concentrations (microU.min/ml) were close: 39286 +/- 4510 (Vitajet) vs 30597 +/- 3575 (conventional). It is concluded that Vitajet constitutes an efficient needleless route for administering insulin pulses.