MON-904 Behind the Mask: The Stories of Insulinoma- a Case Series

Introduction: Insulinoma is a rare, slow growing pancreatic neuroendocrine tumor, leading to hyperinsulinemic hypoglycemia. It runs a very insidious course often masquerading as neurologic, psychological or cardiac disease. We present a series of four cases with varying clinical presentations, diagnoses and latency to diagnosis. Case Report: This is a retrospective analysis of four cases of Insulinoma diagnosed between Sep 2016 and Mar 2019. All the patients were males and aged 36, 22, 63 and 15 years respectively. Baseline characteristics, duration to diagnosis of Insulinoma, diagnosis and treatment given before definitive diagnosis and post-surgery outcomes were analyzed. All the four patients had relatively long latency to diagnosis despite frequent, spontaneous hypoglycemic episodes, longest being ten years. The patients had a neurological and/or psychiatric diagnosis prior to definitive diagnosis. The symptoms improved with consumption of food. One of the four patients was on antipsychotics for episodic abnormal behavior before the diagnosis of Insulinoma. Two of them were on anti-epileptic medications for seizures. All the insulinomas were localized with CECT without requirement for additional localization techniques. All our patients responded well to surgical resection of the tumor. All insulinomas were benign grade 1 tumors. Acanthosis nigricans regressed in all the patients post-surgery. In addition, all the patients had significant weight loss post-surgery. Two of the four patients developed diabetes mellitus and were on insulin therapy. Conclusion: A strong index of suspicion of Insulinoma is warranted while dealing with patients presenting with seizure disorders, behavioral abnormalities and neurological symptoms because the spectrum of symptoms is wide and non-specific. Seeking diagnosis is of utmost importance because of implications on treatment and prognosis. Reference: Valente LG, Antwi K, Nicolas GP, Wild D, Christ E. Clinical presentation of 54 patients with endogenous hyperinsulinaemic hypoglycaemia: a neurological chameleon (observational study). Swiss Med Wkly. 2018 Nov 18;148:w14682.