Insulinoma is generally identified as a single tumor and seldom occurs in children or adolescents. A 14-year-old girl with difficulty in waking was found to have hyperinsulinemic hypoglycemia. On abdominal ultrasonography two hypoechoic masses (8 and 12 mm in diameter) were seen in the pancreatic body: the larger mass was hypervascular, whereas the smaller one was hypovascular. Contrast-enhanced computed tomography showed enhancement of the larger mass, but did not delineate the smaller mass. On fat-suppressed T1-weighted magnetic resonance imaging, the larger mass was hypointense, but the smaller mass was hyperintense. Pathologically, the larger tumor was normal density, insulin positive, and rich in vascularity, whereas the smaller tumor was high density, insulin negative, and poor in vascularity. The present case suggests that difficulty waking should be considered as a potential etiology in insulinoma, and multiple suspected pancreatic insulinomas should be evaluated using a combination of imaging modalities to characterize each tumor.
Keywords: difficulty waking; hypoglycemia; insulinoma; magnetic resonance imaging; ultrasonography.
© 2016 Japan Pediatric Society.