Endocrine Abstracts

Background: Insulinoma is a rare variety of endocrine neoplasm and is usually benign, solitary, and small in size. It is responsible of endogenous insulin secretion resulting in development of symptoms of hypoglycemia.

Case presentation: We report 4 cases of insulinoma that were diagnosed and managed in the year 2022. Three women and one man aged respectively 76, 68, 60 and 42 years-old. All patients presented a long history of various adrenergic symptoms of hypoglycemia and one patient presented signs of neuroglycopenia including behavior changes and confusion. The mean duration of the symptoms was 8.7 years. Three patients presented spontaneous hypoglycemia with a mean plasma glucose levels of 0.3 g/l concomitant with inappropriately high insulin and C-peptide levels. The positive diagnosis was made in one patient after an 8 h fasting test. The tumors were located preoperatively in 3 cases using pancreatic MRI which have objective a unique nodule in all cases with a mean size of 2 cm. in one case, abdominal CT scan, pancreatic MRI and endoscopic ultrasonography were practiced but the tumor was not located. All patients underwent laparotomies and the tumors were localized peroperatively. Enucleation of the nodules were practiced and all the tumors turned out to be benign after histopathological examination. Symptoms disappeared postoperatively in all cases and the glucose plasma levels were normal.

Conclusion: Insulinomas are rare endocrine tumors that can be life-threatening by causing severe hypoglycemia. Clinical manifestations are diverse and the diagnosis is usually delayed. Biochemical diagnosis is easy, but the preoperative localization of the tumor can be challenging. Surgical resection of the tumor is the treatment of choice and should be done by an experienced surgeon. Risk of reoccurrence is rare after surgery and it usually concerns tumors with high histological grade.