IGF-II-secreting bladder tumour presenting as a fall in a 91-year-old

Insulin-like growth factor II (IGF-II)-secreting tumours represent a subset of non-islet cell tumours and are a rare but potentially life-threatening cause of paraneoplastic hypoglycaemia. They are predominantly associated with epithelial or mesenchymal tumours but have also been reported in some hepatocellular carcinomas or retroperitoneal sarcomas. Definitive treatment involves surgical resection of the mass; however, if that is not possible, then various forms of medical management can be trialled. This paper presents the case of a 91-year-old woman admitted to hospital with worsening pelvic pain. Throughout the admission, she was found to have recurrent episodes of hypoglycaemia that, when investigated, were attributed to a bladder tumour. She was diagnosed with an IGF-II-secreting non-islet cell tumour based on imaging, biochemistry, and clinical judgement. Due to her age and limited physical reserve, she declined further investigation or surgical management, leading to trial and successful medical management of her condition. This case highlights a rare presentation of IGF-II-mediated non-islet cell tumour hypoglycaemia arising from the bladder in an elderly patient, which has minimal representation in the literature.

Unexplained and recurrent episodes of hypoglycaemia should raise clinical suspicion of a paraneoplastic process that requires further investigation. It is important to maintain a broad range of differentials when approaching a frail patient with recurrent hypoglycaemia. Management should be guided by discussion with a multidisciplinary team and patient preference. IGF-II-secreting tumours are widely associated with mesenchymal tumours; however, this case presents a rare possible association with bladder tumours. Surgical resection of NICTH tumours is the mainstay of treatment, but when it is not feasible, other medical management should be explored.