Resolution of Refractory Nonislet Cell Tumor Hypoglycemia Following Resection of an Abdominal Solitary Fibrous Tumor.

Introduction: Solitary fibrous tumors are exceptionally rare mesenchymal tumors that can present with paraneoplastic syndromes, the most common being nonislet cell tumor hypoglycemia. We describe a case of refractory hypoglycemia that resolved following surgical resection of a large abdominal solitary fibrous tumor. Case Discussion: A man in his 70s initially presented with abdominal pain and distention. On exam, a firm, nontender, and mobile mass was palpable in the upper abdomen, extending toward the midline. Imaging revealed a 26 cm abdominal mass, and biopsy confirmed solitary fibrous tumor. Two weeks after discharge, he experienced 3 consecutive nights of symptomatic hypoglycemia. Laboratory evaluation showed serum glucose of 27 mg/dL (70-140 mg/dL), suppressed c-peptide 0.2 ng/dL (1.00-4.00 ng/ml), insulin-like growth factor (IGF)-1 of 36 ng/dL (5-34 ng/dL) and IGF-2 of 241 ng/dL (267-616 ng/dL), with an IGF-2:IGF-1 ratio of 6.7:1. The patient underwent surgical resection, and immediately after hypoglycemia was resolved. Discussion: Nonislet cell tumor hypoglycemia is a rare paraneoplastic syndrome caused by ectopic secretion of IGF-2 and it is characterized by severe, recurrent, and treatment-resistant hypoglycemia. It is rare, and diagnosis requires exclusion of more common causes. Definitive management is surgical resection, which typically results in immediate resolution. Conclusion: This case highlights the importance of recognizing paraneoplastic syndrome in patients with unexplained hypoglycemia and underscores the curative potential of timely surgical resection.