Plasma glucagon levels suppressed by a glucose load in a man with incidental pancreatic glucagonoma

Glucagonoma: From skin lesions to the neuroendocrine component (Review)

Glucagonoma is a hormonally active rare pancreatic neuroendocrine tumour causing an excess of glucagon. This is a narrative review based on a multidisciplinary approach of the tumour. Typically associated dermatosis is necrolytic migratory erythema (NME) which is most frequently seen at disease onset. Insulin-dependent diabetes mellitus, depression, diarrhoea, deep vein thrombosis are also identified, as parts of so-called 'D' syndrome. Early diagnosis is life saving due to potential aggressive profile and high risk of liver metastasis. NME as paraneoplastic syndrome may be present for months and even years until adequate recognition and therapy; it is remitted after successful pancreatic surgery. Thus the level of practitioners' awareness is essential. If surgery is not curative, debulking techniques may improve the clinical aspects and even the outcome in association with other procedures such as embolization of hepatic metastasis; ablation of radiofrequency type; medical therapy including chemotherapy, targeted therapy with mTOR inhibitors such as everolimus, PRRT (peptide receptor radiotherapy), and somatostatin analogues (including combinations of medical treatments). Increased awareness of the condition involves multidisciplinary practitioners.

Benign-Appearing Glucagonoma Undergoing Malignant Transformation after a Prolonged Period

Glucagonoma are rare neuroendocrine tumors arising in the Langerhans islets of the pancreas. We report a patient with glucagonoma differentiation into a malignant form after 13 years. A 63-year-old asymptomatic man was evaluated for an enhancing lesion at the distal pancreas. Physical examination was normal. Laboratory values were normal except for an elevated serum glucagon level (206 pg/mL, Ref. 50-150). Somatostatin and other tumor markers were normal. A PET scan confirmed abnormal uptake at the distal pancreas, correlating with a CT scan. The patient underwent laparoscopic distal pancreatectomy with resection of a 2.6-cm mass which predominantly expressed glucagon. Serum glucagon levels normalized immediately postoperatively. He remained asymptomatic for 13 years with normal blood glucose, glucagon, and chromogranin levels and normal surveillance MRI scans. Thirteen years following surgery, an elevated serum glucagon level (230 pg/mL) was observed. At this time he also remained asymptomatic. Abdominal MRI and a PET scan revealed hepatic lesions. Biopsy of the hepatic lesion confirmed metastatic glucagonoma. The patient was treated with lanreotide, which normalized the serum glucagon levels, and the tumor size remained stable for 12 months of follow-up. Complete remission without any treatment for more than 13 years confirmed the benign course of the glucagon-secreting tumor. The precipitating factors are unknown. This case highlights the importance of continuous monitoring of neuroendocrine tumors even beyond 10 years.