Glucagonoma is a rare type of endocrine pancreatic tumor. This means it is a cancer of the glandular endocrine cells of the pancreas rather than the exocrine digestion-related pancreas cells. A “glucagonoma” is a cancer that produces too much production of a hormone called glucagon, which does reduce insulin production. Hence, glucagonoma can interfere with insulin and can give the appearance of diabetes mellitus. However, the effects of too much glucagon are not identical to having too little insulin.
Causes of this pathology remain unknown, although some genetic factors could play an important role, especially in patients who have a family history of multiple endocrine neoplasia type 1 (MEN I) or Wermer syndrome.Glucagonoma is usually malignant (cancerous). The cancer tends to spread and get worse. The cancer affects the islet cells of the pancreas. As a result, they produce too much of a hormone called glucagon.
Nonneoplastic pathologies can elevate glucagon levels that are high enough to produce cutaneous manifestations. Hepatic cirrhosis is an example. Since the liver is responsible for glucagon breakdown, cirrhosis may prolong the effective plasma half-life of glucagon and contribute to abnormally high serum levels. NME with normal glucagon levels has been reported in celiac sprue and pancreatitis; similar skin findings can present with cystic fibrosis.
Causes of this pathology remain unknown, although some genetic factors could play an important role, especially in patients who have a family history of multiple endocrine neoplasia type 1 (MEN I) or Wermer syndrome.
The excess glucagon causes symptoms such as glucose intolerance and hyperglycemia (elevated blood sugar). Spreading of the cancer (metastasis) to the liver may occur. Glucagonoma also cause a distinctive skin lesion called necrolytic migratory erythema.
Glucagonoma is a tumor with a slow rate of growth. Most of the cases start with nonspecific symptoms. In a report of patients with functional pancreatic tumors, the average delay of diagnosis was 3 years. Approximately 50% of cases have metastases at diagnosis. For patients with metastases at diagnosis, the prognosis is poor.
Symptom information has been gathered from various sources, may not be fully accurate, and may not be the full list of symptoms of Glucagonoma. Furthermore, symptoms of Glucagonoma may vary on an individual basis for each patient. Only your doctor can provide adequate diagnosis of symptoms and whether they are indeed symptoms of Glucagonoma.
The primary physiological effect of glucagonoma is an overproduction of the peptide hormone glucagon, which enhances blood glucose levels through the activation of catabolic processes including gluconeogenesis and lipolysis. Gluconeogenesis produces glucose from protein and amino acid materials; lipolysis is the breakdown of fat. The net result is hyperglucagonemia, decreased blood levels of amino acids (hypoaminoacidemia), anemia, diarrhea, and weight loss of 5-15 kg.
All reported glucagonomas with the cutaneous syndrome originated from single pancreatic tumors of considerable size (diameter 1.5–35 cm).(319;327). All tumors occurred in the tail or body of the pancreas, where A cells normally are abundant, deriving from the dorsal anlage of the pancreas. At the time of diagnosis, 62% of the tumors had metastases. Glucagonomas not associated with the syndrome but characterized by morphologic and/or chemical criteria are diagnosed in various ways. First, the tumor may appear as a malignant pancreatic tumor, discovered because of local growth, with or without metastases. Second, the tumor may be associated with an insulinoma, gastrinoma, or as part of the MEN-1 syndrome.