Diagnostic Challenge of Glucagonoma: Case Report and Literature Review

Case of delayed diagnosis of necrolytic migratory erythema

Necrolytic migratory erythema (NME) is a rare cutaneous paraneoplastic manifestation of glucagonoma. We report a case of a woman with a 6-year history of delayed diagnosis of glucagonoma. This case highlights the atypical clinical features of NME which makes the diagnosis difficult.

Unremitting chronic skin lesions: a case of delayed diagnosis of glucagonoma

A 54-year-old Caucasian male with history of hypertension, hyperlipidemia, insulin-dependent diabetes mellitus, and chronic skin rash of 4 years presented to the emergency department with worsening rash and weight loss. Physical examination revealed diffuse erythematous rash, skin ulceration, bullae with associated paresthesia in the lower extremities, trunk, bilateral upper extremities, and palms and soles. A computed tomography (CT) scan with contrast showed a large, heterogenously enhancing pancreatic mass measuring 9.4 × 3.8 cm with surrounding low-attenuation soft tissue thickening. Blood tests showed hemoglobin A1C of 10.0%. Glucagon level was elevated to 2,178 (normal < 80 pg/dl). Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) from the pancreatic mass was suggestive of pancreatic endocrine tumor. The tumor cells were positive for synaptophysin, chromogranin, CD56, and pan-cytokeratin with focal positivity for glucagon, suggestive of glucagonoma. The patient underwent distal pancreatectomy along with splenectomy and cholecystectomy. The glucagon level normalized to 25 pg/dl within a week of tumor resection, and during his 6-week outpatient follow up, skin rash had completely resolved.

Myelodysplastic Syndrome with t(1;7) Associated with Marked Dysmegakarypoiesis & Severe Thrombocytopenia: A Case Report and Review of the Literature

We present the case of a 70-year-old woman who had a bone marrow examination performed to investigate marked thrombocytopenia in the context of a recent history of metastatic glucagonoma. Surprisingly this identified marked dysmegakaryopoiesis and fulfilled diagnostic criteria for refractory cytopenia with multilineage dysplasia, with a relatively uncommon associated cytogenetic lesion t(1;7). We present the case and review the literature of this cytogenetic lesion.

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

OBJECTIVE

To describe a patient with a histologically proven pancreatic glucagonoma, noted incidentally during a follow-up visit for high aminotransferase levels, and to evaluate its autonomy with a standard 75-g oral glucose tolerance test.

METHODS

We present the results of a 2-hour oral glucose tolerance test, with plasma glucagon and blood glucose levels measured every 30 minutes after an oral glucose load. In addition, we provide a brief review of the literature on the diagnosis and management of glucagonomas and the importance of long-term surveillance.

RESULTS

In our patient, who had a 1-year history of impaired fasting glucose, plasma glucagon levels were persistently suppressed to within the normal range after oral glucose challenge. Octreotide scintigraphy revealed abnormal uptake in the pancreatic tail, and a 2.8-cm mass was removed at laparoscopic distal pancreatectomy. Immunohistochemical staining of the tumor tissue showed intense reactivity for glucagon. Plasma glucagon levels were reduced to <50 pg/mL postoperatively, and scintigraphic study at 4-month follow-up showed no residual uptake at the previous tumor site or elsewhere.

CONCLUSION

Glucagon-secreting pancreatic tumors are extremely rare. A substantially elevated plasma level of glucagon is usually seen in patients with metastatic tumors. In the early stage of a glucagonoma, however, the plasma glucagon level may be only modestly elevated and may still be susceptible to normal negative feedback inhibition. We demonstrated plasma glucagon complete suppressibility after oral glucose challenge in a patient with a glucagonoma, the first such report in the literature.