Pathological aspects underlying pancreatogenous hyperinsulinemic hypoglycemia--report of three cases

Pancreatogenous hyperinsulinemic hypoglycemia (PHH) is a rare disorder determined by an abnormally high secretion of insulin in the pancreas, in the absence of other medical or pharmacological factors. Either β-cell tumors (insulinomas) or β-cell hyperplasia (nesidioblastosis) can determine this pathology. Most publications on insulinomas or nesidioblastosis approached these subjects from a clinical point of view. This paper aims to analyze pathological aspects underlying pancreatogenous hyperinsulinemic hypoglycemia. We present two cases of insulinomas with unusual pancreatic localization and size, one of them showing amyloid deposits in the stroma. In both cases, immunohistochemistry confirmed the clinical and imagistic supposition. The third reported case refers to a 57-year-old patient with nesidioblastosis with isolated disposition of endocrine cells and areas of focal organization, both morphological aspects being extremely rare in adults. Although clinical and laboratory data are usually identical in the two forms of PHH, histopathological and immunohistochemical diagnosis is essential in differentiating insulinomas from nesidioblastosis, as the surgical management is different: enucleation for insulinomas and total or subtotal pancreatectomy for nesidioblastosis.