BACKGROUND: Non-islet cell tumor induced hypoglycemia (NICTH) is a very rare 
phenomenon, but even more so in gastrointestinal stromal tumors. It tends to 
present in large or metastatic tumors, and can appear at any time in the 
progression of the disease. We present herein a case of NICTH in a GIST tumor 
and report an exon 9 mutation associated to it.
CASE PRESENTATION: A thirty nine year-old man with a recurrent, metastatic 
gastrointestinal stromal tumor presented to the hospital with nausea, dizziness, 
loss of consciousness, and profound hypoglycemia (20 mg/dL). There was no 
evidence of factitious hypoglycemia. He was stabilized with a continuous glucose 
infusion and following selective vascular embolization, the patient underwent 
debulking of a multicentric 40 cm x 25 cm x 10 cm gastrointestinal stromal 
tumor. After resection, the patient became euglycemic and returned to his normal 
activities. Tumor analysis confirmed excessive production of insulin-like growth 
factor II m-RNA and the precursor protein, "big" insulin-like growth factor II. 
Mutational analysis also identified a rare, 6 bp tandem repeat insert (gcctat) 
at position 1530 in exon 9 of KIT.
CONCLUSION: Optimal management of gastrointestinal stromal tumor-induced 
hypoglycemia requires a multidisciplinary approach, and surgical debulking is 
the treatment of choice to obtain immediate symptom relief. Imatinib or 
combinations of glucocorticoids and growth hormone are alternative palliative 
strategies for symptomatic hypoglycemia. In addition, mutations in exon 9 of the 
tyrosine kinase receptor KIT occur in 11-20% of GIST and are often associated 
with poor patient outcomes. The association of this KIT mutation with non-islet 
cell tumor induced hypoglycemia has yet to be established.