Novel use of somatostatin receptor scintigraphy in localization of focal congenital hyperinsulinism: promising but fallible.

Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycemia in infants and children. The pre-operative differentiation of focal from diffuse forms is extremely important from the management point of view. The current methods for pre-operative differentiation are invasive. We report a patient with CHI where somatostatin receptor scintigraphy was used to diagnose CHI but with limited success. A preoperative 68gallium DOTATOC-PET scan was performed which revealed highly localized radiotracer uptake in the body of the pancreas. 80% of the pancreas including the body was resected. The clinical problems did not completely resolve after surgery. Histopathology revealed hyperplastic islet cells at the resected margin and randomly throughout the pancreas. This case highlights the use of 68gallium DOTATOC-PET scan in a patient with severe CHI. The satellite foci that were missed may be either an inherent limitation of 68Ga DOTATOC scan or an underinterpretation due to lack of expertise. This report opens up a new option of using somatostatin analogue scintigraphy for pre-operative localization of hyperplastic islet cells in patients with CHI.