Pancreatic insulinoma co-existing with gastric GIST in the absence of neurofibromatosis-1

Edward Alabraba, Simon Bramhall, Brendan O'Sullivan, Brinder Mahon, Philippe Taniere

Gastrointestinal stromal tumours (GIST) frequently occur in patients with neurofibromatosis type 1 (NF-1). It has been reported that GIST may co-exist with pancreatic endocrine tumors but this has only been in association with NF-1. A 76 year old woman presented with a 12 month history of hypoglycaemia symptoms. Abdominal CT scan demonstrated a 13 mm insulinoma localized in the tail of her pancreas. She was commenced on diazoxide and later underwent surgery for enucleation of insulinoma when a small (< 1 cm) incidental tumour was discovered on her stomach wall which was identified as GIST. This is the first case report of a pancreatic insulinoma co-existing with a GIST in a patient without NF-1. In addition, we make the first report of rapidly growing cystic GIST recurrence following resection of a primary GIST tumour.