Recurrent Non-islet Cell Tumor Hypoglycemia Secondary to Recurrent Renal Sarcoma

Introduction: Non-islet-cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome encountered in the setting of a wide variety of benign and malignant tumors. Case presentation: A 46 year old lady was referred to our unit, with a large left sided retroperitoneal mass found on surveillance imaging on a background of renal sarcoma 6 years previously, for which she had a left nephrectomy. She had initially presented with symptoms of hypoglycaemia which was a result of tumor secretion of insulin like growth factor 2. She was counselled regarding the recurrence and listed for excision. On the day of surgery she developed symptomatic hypoglycaemia. The tumour was completely resected from the nephrectomy bed. The tumour was histologically identical to the initial tumor. Conclusion: We report a rare case of recurrent non-islet cell hypoglycaemia in a lady with recurrent malignancy. Her hypoglycaemic episodes fully resolved on each occasion following resection. There have been reports of NICTH associated with recurrent retroperitoneal tumours and synchronous thyroid tumours and uterine leiomyomata. NICTH should be considered in patients with a known malignancy who present with recurrent hypoglycaemia. This is, to the best of our knowledge at the time of writing, the first case in the literature of recurrent NICTH secondary to recurrent renal sarcoma.