Retroperitoneal solitary fibrous tumour with Doege-Potter-Syndrome - successful interventional therapy.

BACKGROUND: Solitary fibrous tumours (SFTs) are rare mesenchymal neoplasms that may cause insulin-independent hypoglycaemia (Doege-Potter-syndrome). Although surgical resection is the standard treatment, non-surgical options may be required for elderly or multimorbid patients. CASE PRESENTATION: An 82-year-old woman presented with severe nocturnal hypoglycaemia (<40mg/dl) and progressive weakness. Imaging revealed a large hypervascular retroperitoneal mass. Laboratory findings showed low insulin and C-peptide levels with an IGF-II/IGF-I ratio of 9.3, indicating paraneoplastic hypoglycaemia. Biopsy demonstrated low-grade malignant SFT with STAT6 and CD34 positivity. Because of advanced age and comorbidities, dexamethasone (8mg/day) was initiated, followed by two selective transarterial embolizations over 6 months. Hypoglycaemia resolved rapidly, allowing dexamethasone reducing to 1.5mg/day. At 9-month follow-up, only rare hypoglycaemic episodes remained and were managed with regular meals and low-dose dexamethasone. CONCLUSION: Combined glucocorticoid therapy and selective embolization may provide sustained glycaemic control in elderly patients with retroperitoneal SFT and Doege-Potter syndrome when surgery is not feasible.