Perioperative continuous glucose monitoring during resection of a giant intrathoracic solitary fibrous tumour associated with Doege – Potter syndrome

A man in his late sixties with hypertension and a heavy smoking history presented with a large left thoracic mass. Biopsy confirmed a solitary fibrous tumour. Before his scheduled surgery, he collapsed; his blood glucose level was 40 mg/dL, consistent with insulin-like growth factor-II (IGF-II)–mediated hypoglycaemia (Doege–Potter syndrome). Continuous glucose monitoring (CGM) was initiated to characterise perioperative glucose trends and support glucose management. As his consciousness and oral intake improved with supportive care and adjunctive corticosteroids, his glucose level stabilised, allowing gradual tapering of intravenous glucose. He subsequently underwent complete tumour resection via a hemi-clamshell incision. Postoperatively, his glucose level normalised immediately, and CGM documented the disappearance of fluctuations by postoperative day 2. Fifteen months after surgery, he remained recurrence-free without further hypoglycaemic episodes. Histology confirmed a solitary fibrous tumour, and Western blot analysis demonstrated high-molecular-weight IGF-II. This case highlights how perioperative CGM can support perioperative glucose management in patients with intrathoracic solitary fibrous tumours complicated by Doege–Potter syndrome.