IGF-2 INDUCED HYPOGLYCEMIA ASSOCIATED WITH LUNG SARCOMA

Area of Science:

• Endocrinology
• Oncology
• Paraneoplastic Syndromes

Background:

• Hypoglycemia can arise from non-insulin-secreting extrapancreatic tumors, a paraneoplastic syndrome.
• Tumors produce substances with insulin-like effects, primarily insulin-like growth factor 2 (IGF-2).
• Diagnostic confirmation relies on elevated IGF-2/IGF-1 ratios, though testing availability is limited.

Observation:

• A 70-year-old patient with a right lower lobe bronchopulmonary neoplasm presented with altered general condition and hypoglycemic coma.
• Laboratory evaluation showed low insulin and C-peptide levels.
• An elevated IGF-2/IGF-1 ratio (>10) strongly suggested lung sarcoma producing IGF-2.

Findings:

• The patient was diagnosed with lung sarcoma causing paraneoplastic hypoglycemia via IGF-2 secretion.
• Due to unresectable tumor, treatment included chemotherapy, radiotherapy, and glucocorticoids.
• Glucocorticoid therapy was administered to manage recurrent hypoglycemia.

Implications:

• Prompt recognition of extrapancreatic non-hyperinsulinemic hypoglycemia is crucial for timely diagnosis and treatment.
• In patients with lung sarcoma and recurrent severe hypoglycemia or coma, consider tumor IGF-2 secretion.
• This case underscores the importance of specific diagnostic tests for insulin-like growth factors in unexplained hypoglycemia.