A case of gastrointestinal stromal tumor with hyperinsulinemic hypoglycemia.

Gastrointestinal stromal tumor (GIST) is an uncommon malignant tumor that has recently been drawn to the attention of clinicians because of the protean clinical spectrum, endocrinological pathogenesis, aggressive metastatic features, poor prognosis, oncogenic tyrosine kinase receptor mutation and its brilliant revolutionized inhibitor imatinib. However, very few cases of GIST and hypoglycemia have been reported worldwide and they are usually associated with normal or low insulin levels. Here, we report on a rare case of GIST with postabsorptive hypoglycemia, extraordinary hyperinsulinemia and low insulinlike growth factor I (IGF-I). Its unusual neurological presentation made its diagnosis very difficult. After a complete resection, the symptoms diminished. We point out the unusual endogenous hyperinsulinism, clinical features and postulate possible mechanisms.