8255 Munchausen Syndrome After Partial Pancreatectomy for Insulinoma: A Case Report

Abstract Disclosure: C.R. de Macedo: None. T.D. Bertolacini da Silva: None. I.P. de Magalhães: None. M.A. Pereira: None. I.C. Marques: None. J.L. Pinheiro Filho: None. G.F. Darce: None. D.M. Lourenço Junior: None. Background: Insulinoma is a rare, insulin-secreting pancreatic neuroendocrine tumor, most commonly benign, solitary, sporadic, well differentiated and with a slight female predominance. The investigation of hypoglycemia requires a fasting test to exclude, among other causes, factitious hypoglycemia. Clinical Case: A 27-year-old woman was admitted to the emergency room after seizure by hypoglycemic crisis (capillary blood glucose < 55 mg/dL). She had recurrent episodes of adrenergic/neuroglycopenic symptoms since the age of 14, occurring during fasting, mainly in the morning, with improvement after eating. After confirming Whipple's triad, a fasting test showed hyperinsulinemic hypoglycemia (glycemia 53 mg/dL, normal value >55 mg/dL; insulin 11.5 mcU/mL, nv <3mcU/mL) and increased C-peptide (3.83 ng/mL, nv <0,6 ng/mL). Abdominal magnetic resonance showed a 1.4 cm nodule in the pancreas tail. During hospitalization, she experienced Raynaud's phenomenon, leading to the diagnosis of Raynaud's disease (RD). Distal pancreatectomy was performed, confirming the diagnosis of insulinoma by immunohistochemistry. There was brief remission of the hypoglycemic episodes once they recurred two weeks later. As imaging tests did not show new pancreatic lesions, somatostatin analogue was begun, resulting in improvement for a few more weeks. Due to recurrent hypoglycemia and new seizures, she required continuous intravenous infusion of glucose during hospitalization. A new fasting test revealed hyperinsulinemic hypoglycemia (glycemia 42 mg/dL, insulin 43.3 mcU/mL), low C-peptide (0.5 ng/mL) and normal proinsulin (2.39 pmol/L, nv <5 pmol/L) values. Due RD, auto-immune hypoglycemia was excluded by negative anti-insulin antibodies. Insulinomatosis was also considered, as potential etiology, but review of surgical specimen excluded this hypothesis. After 4 months of hospitalization, due suspicious behavior, a review of her personal belongings revealed insulin vials and needles for injection. The patient confessed to applying insulin to simulate the symptoms, also revealing a history of childhood trauma and previous suicide attempts. After psychiatric evaluation, borderline personality disorder was identified, and Munchausen syndrome was considered. Since then, the patient did not require intravenous glucose with no recurrence of hypoglycemia. Conclusion: The investigation of hypoglycemia can be challenging, requiring appropriate diagnostic protocols. Even in patients who appear to have a well-defined diagnosis, as in our case with anatomopathological confirmation of insulinoma, it is always important to rule out factitious hypoglycemia. The incorrect diagnosis can lead to inappropriate invasive and surgical procedures with definitive consequences, such as exogenous pancreatic insufficiency and insulin-dependent diabetes mellitus. Presentation: 6/1/2024