Thromboembolic pulmonary hypertension of unusual cause in a teenager.

remained above the range to be expected with his blood sugar values. A possible explanation is that some islet cell tumours produce abnormal insulins which are biologically inactive but not immunologically distinct (Samols, 1965). The principal aim of streptozotocin therapy for malignant insulinoma is the restoration of normoglycaemia. This has been achieved in all reported cases. More radical therapy with streptozotocin may be limited by toxicity, but infusion into the coeliac axis may reduce the risk to tissues other than the liver. Complete destruction of neoplastic tissue seems unlikely in this patient, as high plasma insulin levels have persisted.