Introduction: Adult-onset noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS) associated with hyperinsulinemic hypoglycemia is a very rare entity. Clinical features of NIPHS are similar to those of insulinoma. Hypoglycemia with neuroglycopenic symptoms presents the main diagnostic condition. NIPHS is often poorly responsive or unresponsive to medical management necessitating surgical intervention with resection of pancreatic tissue.
Case report: We report case of a 50 years old man that was addmited to our hospital 6 years ago with symptoms of postprandial hypoglycemia with low level of glucose and high level of insulin. Fasting 72 h test was performed and it was positive. CT scan showed small pancreatic lesion and patient underwent surgical resection of pancreas in pursuit of insulinoma. Microscopically and immunohistochemicaly, the pancreas exhibited nodular islet cell hyperplasia and high positivity to chromogranin A and synaptophysin. Six months after surgery patient had symptomatic hypoglycemia again, and fasting 72 h test was positive. Abdominal CT and MRI showed small multifocal pancreatic lesions and suspected hepatic metastasis, whole body scintigraphy with Tc99 m-Tektroyd and CT confirmed pancreatic lesions without hepatic metastasis. Medical management with lanreotide (120 mg subcutaneous injections once monthly) was introduced. For 2 years during treatment with lanreotide patient was euglycemic. Because we excluded metastatic disease we changed medical management from lanreotide to diazoxide. Introduction of diazoxide was associated with improvement. Unfortunately patient stopped treatment with diazoxide and after 2 years he came back with hypoglycemic symptoms and extreme obesity. We again confirmed hyperinsulinemic hypoglycemia with unchanged radiological finding on pancreas and without metastasis. Diazoxide therapy was introduced again.
Conclusion: A rare cause of hyperinsulinemic hypoglycemia in adults can be diffuse pancreatic islet cell hyperplasia. Differentiating between NIPHS and insulinoma is tricky and can present difficulty for treatment.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.