A 30-year institutional experience of insulinoma management at a tertiary care center: a case series.

Background: Insulinomas are rare functional pancreatic neuroendocrine tumors in which accurate preoperative localization is critical yet challenging, particularly in the setting of discordant imaging or atypical pathologies such as islet cell hyperplasia. This study highlights the diagnostic and operative implications of these challenges across three decades of institutional experience. Case Description: We conducted a retrospective review of all patients who underwent surgical resection of biochemically proven insulinomas at our tertiary care center between 1994 and 2024. We included surgical patients with documented hypoglycemia in the presence of inappropriate endogenous hyperinsulinemia. Collected variables included demographics, symptoms, biochemical markers (glucose, insulin, C-peptide, proinsulin), imaging modalities [computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS), fluorodeoxyglucose-positron emission tomography (FDG-PET), and 68Ga-DOTATOC PET/CT], operative details, and postoperative course. Eight patients with a median age of 45 years (range 38-74) underwent surgical treatment for insulinoma. Six were women and six had an American Society of Anesthesiologists (ASA) score of 2. All patients presented with neuroglycopenic symptoms, with four also exhibiting adrenergic symptoms. Diagnosis was achieved biochemically. Preoperative localization demonstrated variable concordance with intraoperative findings, with at least one imaging modality accurately localizing the lesion in five patients. Enucleation was performed in five patients, while three required more extensive resection based on tumor location and proximity to the pancreatic duct. Two patients were found to have islet cell hyperplasia, resulting in persistent hypoglycemia in one case requiring ongoing medical therapy. Median follow-up was 164 days, during which seven out of eight patients achieved biochemical resolution. Conclusions: Insulinoma localization remains challenging despite modern imaging, with discrepancies across modalities impacting surgical planning. 68Ga-DOTATOC PET/CT may offer added value in selected cases. Recognition of atypical pathologies such as islet cell hyperplasia is essential, as it may alter management and outcomes. Surgical strategy should be individualized based on tumor localization and its relationship to the pancreatic duct.