Rare presentation of endocrine pancreatic tumor: a case of diffuse glucagonoma without metastasis and necrolytic migratory erythema.

Glucagonoma is a very rare endocrine pancreatic tumor. At diagnosis, most glucagonomas are malignant and often metastatic. Suspicion of glucagonoma is based on characteristic presentations known as "glucagonoma syndrome". Glucagonoma is often found in the pancreatic body and/or tail and is usually large enough to be localized by computed tomography. We report a case of diffuse glucagonoma necrolytic migratory erythema (NME) in a 45-year-old man with mild diabetes mellitus, mild anemia, and weight loss over 1.5 years. Diffused enlarged pancreas was noted on abdominal ultrasonography incidentally during a routine health check-up. The levels of carcinoembryonic antigen and carbohydrate antigen 19-9 were within normal limits. No enlarged lymph node or extrapancreatic tumor mass was found by several imaging studies. Total pancreatectomy was performed, and the pathology revealed glucagon-producing islet cells and intrapancreatic vascular emboli of tumor cells. He died due to internal bleeding and sepsis after surgery. Presentation of diffuse malignant glucagonoma with tumor emboli but no metastasis or NME is unusual.