Abstract
We describe the case of a 77-year-old man who was admitted with recurrent episodes of altered behaviour. These episodes were related to insulin-like growth factor II (IGF-II) mediated hypoglycaemia. Imaging revealed a large retroperitoneal mass and he underwent debulking surgery uneventfully. Histopathology revealed a solitary fibroma with intense immunostaining positive for CD34 and vimentin, suggesting a mesenchymal origin of the tumour. Later he received chemo/radiotherapy and is on prednisolone with abatement of hypoglycaemic episodes.