# A Case of Pediatric Pancreatic Insulinoma Diagnosed 4 Years after the Onset

## TL;DR

A 12-year-old boy was diagnosed with a rare malignant insulinoma four years after initial symptoms, successfully treated with minimally invasive surgery.

## Contribution

This paper presents a rare pediatric case of malignant insulinoma and discusses treatment and follow-up strategies.

## Key findings

- A 12-year-old boy was diagnosed with a malignant insulinoma after experiencing hypoglycemia for four years.
- The tumor was successfully treated with laparoscopic spleen-preserving distal pancreatectomy, with no further hypoglycemia post-surgery.
- The paper suggests follow-up imaging is acceptable after curative resection, but further surgery may be needed in some cases.

## Abstract

Insulinomas are rare tumors resulting in hyperinsulinemic hypoglycemia. Insulinomas are usually seen in adults, and are very rare in the pediatric population. A total of 10% of insulinomas that occur are associated with multiple endocrine neoplasia type 1, and overall, 10% are malignant.

A 12-year-old boy suffered from an absence-like condition, 4 years before presentation. It was later discovered that this was due to hypoglycemia. His fasting blood glucose level was normal (93 mg/dL), but his insulin level was 60.8 µIU/mL, and his C-peptide level was 4.25 ng/mL, at the first visit. Abdominal CT and MRI showed a 6-cm nodular lesion in the anterior part of the pancreatic tail. Somatostatin receptor scintigraphy revealed radiotracer accumulation in the tumor. There was no evidence of lymphadenopathy or distant metastasis. He underwent laparoscopic spleen-preserving distal pancreatectomy. Pancreatic pathology revealed a grade 2 neuroendocrine tumor and malignant insulinoma. Postoperatively, the patient had no further hypoglycemia. At 9 months after the operation, he was under careful follow-up observation.

We present a pediatric case of a malignant insulinoma that was preoperatively diagnosed as benign and subsequently treated by minimally invasive surgery. There is no clear treatment strategy for pediatric malignant insulinomas. We suggest that—even if malignant insulinoma has been treated by minimally invasive surgery—follow-up with surveillance imaging is acceptable if curative resection has been achieved; however, further surgical intervention may be warranted in selected cases.