Case report: pathological features of aberrant pancreatic development in congenital hyperinsulinism due to ABCC8 mutations.

We describe a patient with congenital hyperinsulinism with previously unreported pathological findings including normal to decreased number of insulin-positive cells with very few enlarged nuclei, aberrant distribution of glucagon-positive cells, and a non-insulin producing adenomatous focus of unusual morphology. Molecular analysis showed that the patient was a compound heterozygote for two mutations of the ABCC8 gene: a previously unreported nonsense mutation (R841X) and a missense mutation (D1471N) that has been previously described. This case suggests that abnormal function of ABCC8 may result in aberrant pancreatic development.