A case report on a protracted course of a hidden insulinoma

• Published in: Annals of medicine and surgery 2021-04, Vol.64, p.102240, Article 102240
• Main Authors: Mohamed Shah, Fatimah Zaherah, Mohamad, Aimi Fadilah, Zainordin, Nur Aisyah, Eddy Warman, Nur’ Aini, Wan Muhamad Hatta, Sharifah Faradila, Abdul Ghani, Rohana
• Format: Article
• Language: English
• Subjects: Case Report; Endogenous hyperinsulinemia; Hypoglycemia; Insulinoma; Neuroendocrine tumor; Selective arterial calcium stimulation test (SACST)
• ISSN: 2049-0801; 2049-0801
• DOI: 10.1016/j.amsu.2021.102240

Insulinoma is a functioning pancreatic neuroendocrine tumor primarily leading due to hypoglycemia due to hypersecretion of insulin. This case illustrates the real challenges faced in the detection of an occult insulinoma, which resulted in a protracted course of the disease. A 33-year-old female presented with recurrent hypoglycemia. Endogenous hyperinsulinemia was confirmed by a prolonged fast, however serial imaging was negative. Incidental finding of an ovarian mass gave rise to the suspicion of an insulin-producing ovarian tumor. Subsequent multimodality pancreatic imaging remained negative, requiring more invasive investigations. The tumor was localized by specialized arteriography using calcium stimulation to support the diagnosis of an insulinoma. However, repeated negative imaging led to further delays in definitive management, with worsening hypoglycemia. The surgery was finally performed three years after the initial presentation with successful removal of the tumor using intra-operative ultrasound. It is important to emphasize that preoperative radiological imaging is useful to localize pancreatic lesions. However, most insulinomas could only be detected intraoperatively. The absence of suggestive radiological evidence should not deter surgeons from proceeding with definitive surgical intervention. The case highlights the importance of a multidisciplinary approach in the management of a complicated case. •Insulinoma is a difficult disease to diagnose due to its ambiguous location and insidious course.•Insulinoma and type 2 diabetes mellitus coexistence is rare.•Radiological imaging has improved in aiding the detection of pancreatic lesion but falsely negative results remain high.•Surgical intervention is imperative for explorative diagnosis as well as treatment.•A multidisciplinary approach could have been more successful in early detection and thus providing definitive treatment.