Case Report
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jun 26, 2022; 10(18): 6227-6233
Published online Jun 26, 2022. doi: 10.12998/wjcc.v10.i18.6227
Insulinoma after sleeve gastrectomy: A case report
Miry Lobaton-Ginsberg, Pilar Sotelo-González, Claudia Ramirez-Renteria, Fany Gabriela Juárez-Aguilar, Aldo Ferreira-Hermosillo
Miry Lobaton-Ginsberg, Facultad de Medicina, Universidad Anáhuac México Norte, Mexico City 52786, Mexico
Pilar Sotelo-González, Servicio de Endocrinología, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, IMSS, Mexico City 06720, Mexico
Claudia Ramirez-Renteria, Aldo Ferreira-Hermosillo, Unidad de Investigación Médica en Enfermedades Endocrinas, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
Fany Gabriela Juárez-Aguilar, Servicio de Anatomía Patológica, Hospital de Especialidades del Centro Médico Nacional Siglo XXI, IMSS, Mexico City 06720, Mexico
Author contributions: Lobaton-Ginsberg M participated in the conception and design of the report and wrote the paper; Sotelo-González MP made substantial contributions to the acquisition, analysis, and interpretation of the patient data and helped write the paper; Juárez-Aguilar FG performed the histopathological and immunohistochemical report; Ramírez-Rentería C and Ferreira-Hermosillo A were involved in the coordination and design of the report and the revision of the manuscript; all authors read and approved the final manuscript.
Informed consent statement: Informed written consent was obtained from the patient for the publication of this report and any accompanying images.
Conflict-of-interest statement: The authors declare that they have no conflict of interest to disclose.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Aldo Ferreira-Hermosillo, MD, MSc, Research Scientist, Unidad de Investigación Médica en Enfermedades Endocrinas, Instituto Mexicano del Seguro Social, 330 Cuauhtémoc, Doctores, Mexico City 06720, Mexico.
Received: December 13, 2021
Peer-review started: December 13, 2021
First decision: January 8, 2022
Revised: January 24, 2022
Accepted: April 28, 2022
Article in press: April 28, 2022
Published online: June 26, 2022

Laparoscopic sleeve gastrectomy (LSG) has been proposed as an effective and durable treatment for severe obesity and glucose metabolism disorders, and its prevalence has increased from 5% to 37% since 2008. One common complication after bariatric surgery is a postprandial hyperinsulinemic hypoglycemic state. While rare, insulinomas can cause this state, where symptoms are more common in the fasting state; thus, evaluation of insulin secretion is needed. Until now, there have been no reports of insulinoma after LSG.


We describe the case of a 43-year-old woman who was referred to the obesity clinic 2 years after LSG was performed. She had symptoms of hypoglycemia predominantly in the fasting state and documented hypoglycemia of less than 30 mg/dL, which are compatible with Whipple’s triad. Initially, dumping syndrome was suspected, but after a second low fasting plasma glucose was documented, a 72-h fasting test was performed that tested positive. Computed tomography and endoscopic ultrasound were performed, identifying the presence of a homogeneous hypoechoic semioval tumoral lesion in the pancreas. The diagnosis was compatible with insulinoma. After laparoscopic enucleation of the insulinoma, the symptoms and hypoglycemia disappeared. The histopathological report described a well-differentiated grade 2 neuroendocrine tumor with positive chromogranin and synaptophysin and Ki67 immunopositivity in 4% of the neoplastic cells.


Insulinoma after LSG is a rare condition, and clinicians must be aware of it, especially if the patient has hypoglycemic symptoms during the fasting state.

Keywords: Insulinoma, Hypoglycemia, Bariatric surgery, Glucagon-like peptide 1 amide, Neuroendocrine tumors, Case report

Core Tip: Neuroglycopenic symptoms compatible with Whipple’s triad were identified in a woman 2 years after laparoscopic sleeve gastrectomy, predominantly occurring in the fasting state. After discarding late dumping syndrome, a 72-h fasting test was performed and tested positive. Imaging techniques documented the presence of a tumoral lesion in the pancreas, compatible with insulinoma. After laparoscopic enucleation of the insulinoma, the symptoms were relieved. When hypoglycemia occurs after bariatric surgery, evaluation of insulin secretion is needed to conduct a correct diagnostic approach. Follow-up must be performed by a multidisciplinary team.