Cystic Glucagonoma: A Rare Variant of an Uncommon Neuroendocrine Pancreas Tumor

Glucagon-producing neuroendocrine tumors typically present with a characteristic constellation of symptoms including necrolytic migratory erythema, non-insulin-dependent diabetes, weight loss, anemia, glossitis, and an increased thrombotic tendency. Most glucagonomas are solid and arise in the body or tail of the pancreas. We report two cases of cystic glucagonoma, one found incidentally in an asymptomatic patient and one in a patient with weight loss and diabetes but no rash. In the first patient, distal pancreatectomy and splenectomy were curative, whereas the second patient continued to exhibit elevated serum glucagon levels and symptoms of glucose intolerance in the absence of demonstrable metastases. Cystic glucagonoma is a unique variant of classic glucagonoma and should be considered in the differential diagnosis of cystic pancreatic neoplasms.