Metastatic insulinoma in a patient with type 2 diabetes mellitus: case report and review of the literature

Abstract

Pancreatic neuroendocrine tumors (NETs) are extremely rare, and although insulinomas are the commonest, less than 10% of insulinomas are malignant. Most patients with insulinomas present with neuroglycopenic symptoms and weight gain attributable to insulin excess. Here, we report a case where a 67-year-old lady with a background history of type 2 diabetes mellitus and breakthrough hyperinsulinism who presented with coma. The biochemical profile revealed features typical of insulinoma, and CT and endosonography confirmed a pancreatic tumor with large volume right-sided liver metastases (biopsy confirming a neuroendocrine tumor). The patient underwent successful one-step RO surgical resection, distal pancreatectomy, splenectomy, and right hepatectomy, and 9 months postoperatively, she remains free of recurrent disease. She remains a diabetic.

Figure 1

MD-CT scan demonstrating a hypodense lesion (arrow) with spots of peripheral calcifications in the body/tail of pancreas as wells as a large hypodense liver metastasis in the right lobe of liver, arrow (b). (c, d) show at endoscopic ultrasound the presence of the heterogeneous hypoechoic mass involving the body and tail of pancreas with numerous hypoechoic well defined peri-pancreatic lymph nodes (d).

Figure 2

US-guided liver biopsy staining H & E (a) demonstrating a rather uniform population of sheets of small cells arranged in manner (×40 in (b)). Immunohistochemistry with a Ki-67 marker (Mib-1) (c) estimated here to be 15% and positive immunostaining with chromogranin A (d).