Nonfunctioning endocrine tumor arising from intracranial ectopic pancreas associated with congenital brain malformation.

CASE REPORT: We report a case of a nonfunctioning pancreatic endocrine tumor arising from intracranial ectopic pancreatic tissue. HISTORY: An 11-year-old girl was admitted to our hospital with a brain tumor. Hydrocephalus and brain malformation were apparent at birth. We first identified a mass-like lesion in the child's brain at age 4 months. We monitored the lesion yearly by magnetic resonance imaging (MRI) until she reached age 11 years. Gadolinium-enhanced MRI showed the lesion to be a tumor, which was resected. PATHOLOGY: Examination of surgical specimens revealed a mature pancreatic tissue. We also identified monotonous neoplastic cells with round nuclei and positive immunoreactivity for synaptophysin, chromogranin A, and neurospecific enolase. However, these cells were negative for pancreatic endocrine markers. We diagnosed nonfunctioning pancreatic endocrine tumor arising from intracranial ectopic pancreatic tissue.
CONCLUSION: Migrating pancreatic elements may have induced brain malformation during embryonic development and subsequently become malignant.