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

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.

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.

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.

This case highlights the importance of recognizing paraneoplastic syndrome in patients with unexplained hypoglycemia and underscores the curative potential of timely surgical resection.