Hyperinsulinemic hypoglycemia due to adult nesidioblastosis in insulin-dependent diabetes

Abstract

In neonates, persistent hyperinsulinemic hypoglycemia (PHH) is associated with nesidioblastosis. In adults, PHH is usually caused by solitary benign insulinomas. We report on an adult patient who suffered from insulin-dependent diabetes mellitus, and subsequently developed PHH caused by diffuse nesidioblastosis. Mutations of the MEN1 and Mody (2/3) genes were ruled out. Preoperative diagnostic procedures, the histopathological criteria and the surgical treatment options of adult nesidioblastosis are discussed. So far only one similar case of adult nesidioblastosis subsequent to diabetes mellitus II has been reported in the literature. In case of conversion of diabetes into hyperinsulinemic hypoglycemia syndrome, nesidioblastosis in addition to insulinoma should be considered.

Figure 1

Histopathological features of diffuse nesidioblastosis. A: HE stained sections demonstrating a prominent lobulation of an islet. Some of the endocrine cells showing hyperchromatic and enlarged nuclei are labelled with arrows. B, C: Adjacent section analysis demonstrating cytoplasmic positivity for proinsulin (PRO-INS) in those endocrine cells with hyperchromatic nuclei (arrows in B). In contrast, these cells are negative for somatostatin (SOM) (arrows in C).