Endocrine Abstracts

Introduction and importance: Insulinoma is a rare pancreatic neuroendocrine tumor characterized by hypersecretion of insulin, leading to neuroglycopenia symptoms and heightened sympathoadrenal activity. Incidence ranges from 1 to 4 cases per million inhabitants annually, with a predilection for females in their fourth or fifth decade. Despite its rarity, underdiagnosis is suggested by autopsy studies, revealing higher prevalence. Clinical manifestations often mimic other conditions, causing diagnostic delays. Insulinomas can be sporadic or linked to genetic predispositions like type 1 multiple endocrine neoplasia (MEN1). Diagnosis involves clinical and biochemical assessments, with confirmation through tumor localization using non-invasive imaging techniques and for difficult cases invasive modalities could be needed.

Case presentation: We present a case involving a 61-year-old patient who experienced recurring episodes of malaise for over four years, initially misdiagnosed and treated as Parkinson’s disease. Upon admission for the investigation of hypoglycemic episodes, the patient underwent a fasting test that indicated endogenous hyperinsulinism based on elevated insulin and C-peptide levels: 18.43 μUi/ml and 4.84 ng/ml. While a CT scan showed no abnormalities, a pancreatic MRI also revealed no lesions; however, an endoscopic ultrasound identified a 5mm lesion in the upper part of the pancreatic body. Subsequent enucleation of the lesion confirmed its neuroendocrine nature through histopathology.

Conclusion: In summary, insulinomas, while usually benign and treatable, pose a risk of misdiagnosis, particularly as their symptoms overlap with epilepsy and psychiatric conditions. Despite their rarity, these tumors can be life-threatening due to severe hypoglycemia, emphasizing the need for continued clinical follow-up post-surgery. The diagnostic challenge, often requiring invasive measures for accurate localization, highlights the importance of a vigilant and multidisciplinary medical approach for effective management.