Endocrine Abstracts

Introduction: Insulinoma is a rare tumor, with peak incidence at 30 -60 years of age and more frequent in women. It is associated with a myriad of clinical manifestations: from clearly defined adrenergic and neuroglycopenic symptoms to asymptomatic hypoglycemia. We present the case of a 20-year-old patient with pancreatic insulinoma, which was surgically resected only after her second hospitalization due to repeated negative imaging.

Case presentation: A 20-year-old female patient presented in the Emergency Department in a stuporous state, following an episode of left hemiparesis, numbness and urinary incontinence. She had a three-month history of weakness and somnolence during the day but didn’t suffer from any disease. Her blood glucose in admission was 24 mg/dl. After IV glucose administration, she recovered completely and was hospitalized for further evaluation of her hypoglycemia. During her hospital stay, she experienced episodes of tiredness and somnolence associated with fasting and postprandial hypoglycemia, in 2–3-hour intervals. In a blood sample after 8 h of fasting, her glucose was 24 mg/dl and insulin 17.4 µU/ml (≥ 3 µU/ml). Abdominal CT and MRI with contrast were negative. She was discharged from the hospital under diet tips for insulinoma to prevent hypoglycemia and Diazoxide treatment. Her low glycemic values continued despite the diet and up-titration of the Diazoxide dosage, which resulted in subsequent adverse reactions (palpebral edema, lip swelling, malaise and later, hirsutism). Having no improvement in her glycemic profile, Diazoxide was then stopped. In her second hospitalization 3 months later, her measured Insulin and C-peptide levels were very high with a blood glucose of merely 22 mg/dl. MRI with contrast identified a pancreatic lesion 11x9mm with no contrast enhancement. Surgical excision was performed and biopsy confirmed insulinoma. Glycemic values returned to the normal range but two weeks following surgery, our patient had acute pancreatitis and underwent a second surgical intervention. She discharged 2 weeks later in a good general condition.

Conclusion: Diagnosis of insulinoma in a young patient can be challenging, because the symptoms usually are atypical and nonspecific, and may precede the detection of a lesion. A careful imaging evaluation is necessary to identify the lesion early, with the aim of its surgical removal as soon as possible.