Endocrine Abstracts

An 87-year-old lady was admitted to hospital with severe unexplained hypoglycaemia with capillary glucose of 1.8 mmol/l and went on develop recurrent episodes of symptomatic hypoglycaemia during this admission. She had a background history of diabetes mellitus, well under controlled with diet and a previous diagnosis of solitary fibrous pleural tumour of left lung, which was resected completely in 2013 but reoccurred in 2022 with left sided pleural effusion. Her liver and renal function tests were within normal reference range. She has a normal cortisol response to synacthen test as follows: 335nmol/l at zero minutes, 955 nmol/l at 30 minutes and 1066nmol/l at 60 minutes. CT chest showed a 22 cm solid lesion in the left hemithorax, which had enlarged, considerably in comparison with previous scans and represented a recurrence. Laboratory assessment during one of the hypoglycaemic episodes (venous glucose 1.3 mmol/l (3.6-5.4)) revealed a C-peptide of 25 pmol/l(normal range 370- 1470 ) and insulin level of < 12 pmol/l ( normal level 18-173). Paraneoplastic hypoglycaemia likely due to NICTH was suspected, however IGF-2 level could not be processed due to unavailability of radiolabelled assay. She was deemed an unsuitable candidate for further operation and chemotherapy by the lung multi-disciplinary team. An initial attempt to treat hypoglycaemia with a tapered dose of prednisolone failed, so she was continued on oral prednisolone 15 mg once a day. Unfortunately, hypoglycaemia (capillary blood glucose 1.7mmol/l) re-occurred and she was re-admitted to hospital and Prednisolone dose was increased to 30 mg once day. If this fails Growth hormone injection will be next available treatment option for her although her prognosis is poor in view of the advanced neoplastic disease.

Discussion: • NICTH is a rare cause of paraneoplastic hypoglycaemia and is mostly seen in mesenchymal and epithelial tumours • It is due to an underlying tumour producing excessive insulin like growth factor (IGF-2) or pro IGF-2. • It can cause profound and persistent hypoglycaemia and may not respond to medical treatment and the main stay of treatment is surgical excision of underlying tumour