Endocrine Abstracts

Case History: A 51 year old man was brought in by ambulance with new confusion was found to have hypoglycaemia with a blood glucose of 1.8. He was treated by paramedics. His PMHx included a recent diagnosis of solitary pleural fibrous tumour, recent diagnosis of epilepsy. The patient had been admitted to hospital 10 weeks ago with recurrent confusions. Collateral history unveiled visual hallucinations. He had recently lost unintentional weight. Random blood glucose at first presentation was in range. During his work up on the very first presentation showed right sided pleural based mass. A CT scan of the thorax, abdomen and pelvis showed an unusual large mass in the right hemithorax. Histopathology showed a benign solitary pleural based fibrous tumour. Lung MDT concluded that surgical resection should be the mainstay of treatment. For his confusion neurologist review was sought which resulted in a diagnosis of possible epilepsy and arranged for a battery of investigations and MRI scan which were all normal. He was commenced on anti-epileptics, however despite increasing the dose of multiple anti-epileptics his episodes of confusion was becoming more severe and more frequent. As he was found to have hypoglycaemia for the first time on this latest admission. We investigated him for Insulinoma and paraneoplastic IGF-2 driven hypoglycemia from pleural fibroma. Investigations confirmed IGF-2 driven hypoglycemia and he was cured after surgical resection. He has not had any hypoglycaemia since surgery.

Investigation: Plasma Blood Glucose 2.3 mmol/l (3.6-6.1) Insulin levels at the time of hypoglycaemia: <1pmol/l C-peptide at the time of hypoglycaemia: <103 pool/l Oral Hypoglycemic screening at the time of hypoglycaemia Negative Beta-hydroxybutyrate at the time of hypoglycaemia 0.2 mmol/l Insulin antibodies Negative IGF-I 6.6 nmol/l (13.4-62.1) IGF-II 136.6 nmol/l IGF I: IGF II ratio 20.7 (<10) Cortisol 334 mol/l, TSH 3.46 NMDA receptor Ab negative VGKC Ab negative Anti-GAD Ab negative. CT-TAP showed pleural based tumour with no other abnormality MRI head normal.

Results and Treatment: The results confirmed that he had IGF-II driven hypoglycemia from the pleural fibroma (Doege Potter Syndrome). He underwent surgical resection of the tumour. After surgery he has not had any hypoglycemia. Post-surgery he has recovered well and has come anti-epileptic medications.

Conclusion: • Thorough and systematic work-up of non-diabetes related hypoglycaemia is essential.• In patients with a background of a known tumour presenting with neurological symptoms considering paraneoplastic syndromes is important.