# Pancreatic Neuroendocrine Tumors—Diagnostic Pitfalls of Non-Diabetic Severe Hypoglycemia: Literature Review and Case Report

## TL;DR

This paper discusses the diagnostic challenges of non-diabetic severe hypoglycemia caused by pancreatic neuroendocrine tumors, using a case report and literature review.

## Contribution

The paper highlights the importance of multidisciplinary collaboration in diagnosing and managing hyperinsulinemic hypoglycemia due to insulinoma.

## Key findings

- A 57-year-old patient with non-diabetic hypoglycemia was diagnosed with a pancreatic neuroendocrine tumor.
- Postoperative recovery showed normalization of hypoglycemia and insulin levels.
- Multidisciplinary collaboration is crucial for diagnosing and treating hyperinsulinemic hypoglycemia.

## Abstract

Background: Hypoglycemia in the case of persons without diabetes is a rare event, being usually, initially misinterpreted based on the symptoms that can mimic various diseases, especially of a neuro-psychiatric nature. In the case of the identification of insulin-mediated hypoglycemia, the evaluation of pancreatic neuroendocrine tumors, which represent the most common and worrisome causes of non-diabetic insulin-mediated hypoglycemia, must be considered. Case Report: We present the case of a 57-year-old patient, hospitalized for a history of approximately one month of recurrent episodes of symptoms suggestive for severe hypoglycemia. The biological evaluation performed during an episode of hypoglycemia showed a plasma glucose value of 44 mg/dL, insulinemia 16.3 µU/mL, C peptide 3.72 ng/mL, HbA1c 4.99%, absence of urinary ketone bodies and anti-insulin antibodies <0.03 U/mL. The CT and MRI examination showed a 15.3/15 mm rounded tumor in the pancreatic corporeo-caudal region. The pancreatic tumor formation was enucleated and the histopathological and immunohistochemical analysis confirmed the diagnosis of the pancreatic neuroendocrine tumor with a positive reaction for chromogranin A, synaptophysin and insulin, without malignancy features (Ki 67 positive in 1% of the tumor cells). The postoperative evolution was favorable, without episodes of hypoglycemia, the fasting insulinemia one day after surgery being 4.1 µU/mL and HbA1c at three weeks postoperatively being 5.51%. Conclusions: The management of patients with hyperinsulinemic hypoglycemia secondary to insulinoma involves multidisciplinary collaboration with an important role in recognizing symptoms suggestive of hypoglycemia in a person without diabetes, initiating biological and imaging evaluation, establishing the optimal therapeutic option and histopathological confirmation.