Glucagonoma and pseudoglucagonoma syndrome

Glucagonoma syndrome may present either associated with a pancreatic neoplasm which secretes glucagon or as a pseudo-glucagonoma associated with other diseases. It is extremely infrequent but well-known with a current prevalence estimated at 1/20,000,000.

A retrospective review of glucagonoma and pseudoglucagonoma cases observed between January 1998 and December 2003 in three hospitals.

Five cases: 3 with a demonstrable glucagon-secreting tumor and 2 cases without an associated neoplasm.

Age, sex, initial diagnosis, associated symptoms, and pathology were analyzed as were procedures employed in diagnosis, imaging studies, laboratory data, surgery and follow-up.

Hyperglycemia and elevated plasma glucagon levels were found in all cases. In 3 cases, hypo-aminoacidemia and a descrease in fatty acids were found. No changes of zinc levels were observed. Abdominal ultrasound studies were of no value except in evaluating pancreatitis. A CT-scan was conclusive when a pancreatic neoplasm existed and 3 patients were operated on a curative basis.

Necrolytic migratory erythema was the key diagnosis in all cases. Surgery was intended to be curative. The follow-up was of 8, 37 and 57 months in the cases of true glucagonoma syndrome.

A real prevalence of glucagonoma syndrome could be greater than currently estimated. In our series, it was 13.5/20,000,000. Pseudoglucagonoma syndrome remains a rarity.