IGF2 and gastrointestinal stromal tumor: None of the reported cases of co-existent GIST and GEP NE tumours in NF-1 patients has ever involved an insulinoma and in fact the only report of hypoglycaemia associated with GIST was attributed to a rare paraneoplastic syndrome caused by over-expression of insulin-like growth factor II [15] in an advanced gastric GIST.