Perioperative Continuous Glucose Monitoring During Resection of a Giant Intrathoracic Solitary Fibrous Tumour Associated With Doege-Potter Syndrome.

A man in his late 60s with hypertension and a history of heavy smoking presented with a large left thoracic mass. A biopsy confirmed a solitary fibrous tumour. Before his scheduled operation, he collapsed; his blood glucose level was 40 mg/dL, consistent with insulin-like growth factor-II-mediated hypoglycaemia (Doege-Potter syndrome). Continuous glucose monitoring was initiated to characterize perioperative glucose trends and support glucose management. As his consciousness and oral intake improved with supportive care and adjunctive corticosteroids, his glucose level stabilized, allowing gradual tapering of intravenous glucose. He subsequently underwent complete tumour resection via a hemi-clamshell incision. Postoperatively, his glucose level normalized immediately, and continuous glucose monitoring documented the disappearance of fluctuations by postoperative day 2. Fifteen months postoperatively, he remained recurrence-free without further hypoglycaemic episodes. Histologic analysis confirmed a solitary fibrous tumour, and Western blot analysis demonstrated high-molecular-weight insulin-like growth factor-II. This case highlights how perioperative continuous glucose monitoring can support perioperative glucose management in patients with intrathoracic solitary fibrous tumours complicated by Doege-Potter syndrome.