Surgical Treatment of Insulinoma – Case Report

Abstract

Background

Among the rare functional pancreatic neuroendocrine tumors, insulinoma is the most common. The tumor is on most cases an intraparenchymal solitary mass. The pathophysiological finding of insulinoma is hypoglycaemia, often severe, manifested with non-specific symptoms, which makes the diagnosis difficult. Hypoglycaemia in insulinoma is organic and confirmed with elevated levels of serum insulin after a prolonged fasting test. Localization of the tumor is the next diagnostic challenge. A combination of tomographic imaging techniques such as MRI and CT scan, endoscopic ultrasonogram and nuclear medicine has improved the preoperative evaluation. The mainstay treatment of insulinoma is surgery, which has evolved from blind pancreatectomy to surgical excision by enucleation.

Case presentation

The 44 years old female patient was transferred to the Endocrinology Department of “Mother Theresa” University Hospital Tirana, Albania for examining the cause of hypoglycaemia. Following a MRCP with contrast, an insulinoma at the level of the body of pancreas was noted. Its dimensions reach 11mm. The joint staff consult recommended a surgical treatment. Reviewing omental bursa, we find a formation at the level of the body of pancreas.The margins of the pancreas are carefully dissected and simultaneously the pancreatic capsula at the formation level is prepared step by step, ensuring hemostasis and continuity of the ductus of Wirsung. The extirpation of insulinoma is achieved, without damaging the pancreatic duct, as such a complication would require another treatment modality.

Discussion

The preoperative evaluation of insulinoma patients is a crucial aspect of the successful treatment. Patients should be thoroughly questioned for the lifestyle habits and diet; also, complete hormonal panel and tests should be performed for organic hypoglycaemia. Next step on the correct diagnosis is the imaging and tumor location. It is advised to perform triphasic abdominal Computed Tomography. With the development of Endoscopic Ultrasound, it has cemented its role as a sensitive and reliable examination, capable of fine needle aspiration when indicated. Other procedures include Magnetic Resonance Imaging (MRCP), PET/CT and somatostatin receptor scintigraphy.

The surgical approach is dependent on the location of the tumor and its distance to the Wirsung ductus. Some procedures include caudal pancreatectomy, resection of the uncinate process, central pancreatectomy. Enucleation is advised wherever possible to preserve parenchyma.

Conclusion

When the tumor has been evidenced, the next step for the surgeons to decide the best surgical procedure (excision and parynchyma sparing, or pancreatectomy). The open surgical approach is currently advised as there is no clear consensus on the benefits of the minimal invasive laparoscopic route.

On this specific case the abdominal computed tomography was unable to identify the location of the tumor. Other diagnostic options are thus indicated. Following MRCP, the localization in the body of pancreas of insulinoma was confirmed. During the surgery the continuity of Wirsung ductus was preserved, and a complete enucleation of the tumor performed.

Keywords: General Surgery, Pancreatic Cancer, Pancreas Tumor, Insulinoma, Pancreatic Resection.

DOI: 10.7176/JEP/14-29-03

Publication date:October 31^st 2023