The
glucagonoma syndrome is characterized by a necrolytic migratory erythematous
rash, angular
stomatitis, painful
glossitis, a normochromic normocytic
anemia, mild
diabetes mellitus,
weight loss, a tendency to
thrombosis, and neuropsychiatric disturbances. The diagnosis is made by finding a high plasma
glucagon concentration in the absence of any other cause, such as
renal failure or severe stress. A pancreatic alpha-cell
tumor can be identified and stained by immunocytochemistry with
glucagon antibodies. Optimal treatment is surgical removal, but approximately 50 percent of the
tumors have metastasized by the time of diagnosis. Since the
tumor is slow-growing, remission can be obtained by hepatic artery embolization to shrink hepatic secondaries or by shrinkage, in about 10 percent of patients, with the combination chemotherapeutic regimen of
5-fluorouracil and
streptozotocin. The
rash frequently responds to administration of
zinc, a
high-protein diet, and control of the diabetes with
insulin. Alongside the alpha cell in the islets of Langerhans is the D-cell, which produces
somatostatin and may well act physiologically as a paracrine inhibitor of
glucagon release. A newly developed, long-acting
somatostatin analogue,
SMS 201-995, which the patient can self-administer as a
subcutaneous injection, has proven effective in suppressing
glucagon secretion from
glucagonomas and, in some cases, causing remission of clinical symptoms.