Insulinoma in childhood: a retrospective review of 22 patients from one referral centre

Background

Insulinomas are very rare in childhood with sparse knowledge on the clinical aspects and the presence of Multiple Endocrine Neoplasia type 1 (MEN1).

Methods

We conducted a retrospective review of patients diagnosed with insulinoma between 1995 and 2021, presenting to one referral centre in Russia. Clinical, biochemical, genetic, imaging and histological data were collected. In addition, follow-up and family data were obtained.

Results

A total of twenty-two children aged 5 to 16 years were identified. The median (range) gap between the first hypoglycaemia symptoms and diagnosis was 10 (1-46) months. Twelve children (55%) were misdiagnosed to have epilepsy and were treated with anticonvulsants before hypoglycemia was revealed. Contrast enhanced MRI and/or CT were accurate to localize the lesion in 82% (n=18). Five patients (23%) had multiple pancreatic lesions. All children underwent surgical treatment. The median (range) diameter of removed tumors was 1.5 (0.3-6) cm. Histopathological studies confirmed the presence of insulinoma in all cases. Immunohistochemical studies revealed G2 differentiation grade in 10 out of 17 cases. Two patients were diagnosed with metastatic insulinoma. One of them had metastases at the time of insulinoma diagnosis, while the other was diagnosed with liver metastases eight years after the surgery. Eight children (36%) were found to carry MEN1 mutations, inherited n=5, de novo n=1, no data, n=2. Children with MEN1 had significantly higher number of pancreatic tumors compared to sporadic cases. All of them developed additional MEN1 symptoms during the following 2-13 years. In the five patients with inherited MEN1, seven family members had hitherto undiscovered MEN1 manifestations.

Conclusions

In this large cohort of children with rare pediatric insulinomas, MEN1 syndrome and G2 tumors were frequent, as well as hitherto undiscovered MEN1 manifestations in family members. Our data emphasize the need of genetic testing in all children with insulinoma and their relatives, even in the absence of any other features, as well as the importance of a prolonged follow-up observation.

Insulinoma masquerading as a loss of consciousness in a teenage girl: case report and literature review

BACKGROUND

Hypoglycemia due to a pancreatic beta cell neoplasm - insulinoma, is uncommon with only a few cases described. We report on a previously healthy 15-year-old Hispanic female with insulinoma who presented with a loss of consciousness due to hypoglycemia unawareness.

CASE PRESENTATION

EM was first brought to the emergency department (ED) after she was found unresponsive at home with point of care (POC) glucose of 29 mg/dL(1.6 mmol/L) documented by emergency medical services (EMS) upon arrival. After treatment with dextrose and normal laboratory evaluation, including complete blood count, basal metabolic profile and urine drug screen, she was sent home with recommendations to follow-up the next day with an endocrinologist. Due to insurance issues, the family did not keep the appointment. Two days later, she returned to the ED with POC of 19 mg/dL (1.05 mmol/L). Detailed history review identified vague fatigue, excessive sleepiness, poor oral intake and weight gain for a 2-3 month period and no suspicion for drug, alcohol or prescription medication abuse. Family history of multiple endocrine neoplasia was negative. Physical examination revealed mild acanthosis nigricans and a body mass index of 32.8 kg/m² (98th percentile). Laboratory evaluation showed elevated insulin with low cortisol and growth hormone levels at the time of hypoglycemia. Abdominal magnetic resonance imaging revealed a pancreatic mass, also supported by ultrasound, computed tomography and positron emission tomography scans. The patient underwent a partial pancreatectomy with removal of a well-circumscribed insulinoma from the anterior-superior aspect of the pancreatic neck confirmed by histology. Hypoglycemia resolved post-operatively and she remained euglycemic during a 48-h cure fast. At her 3-month follow-up visit, she had no symptoms of hypoglycemia.

CONCLUSION

Documented hypoglycemia in an otherwise healthy adolescent should be fully investigated before discharging a patient. Even a short duration of symptoms should prompt, in-depth diagnostic evaluations to rule out a potentially life threatening diagnosis of insulinoma.