Imaging features of glucagonoma syndrome: A case report and review of the literature

Abstract

Abstract. Glucagonoma syndrome appears as an extremely rare neuroendocrine tumour, with few studies ever having detailed its imaging manifestations. In particular, the magnetic resonance imaging (MRI) features of the lesion have not yet been reported. The present study describes a 54-year-old male who presented with uncontrollable skin erythema and weight loss that had been apparent for two years, and diabetes mellitus that had been apparent for five years. The glucagon level was 180 pg/ml. The plain abdominal computed tomography (CT) scan revealed a solid tumour in the neck of the pancreas, which was slightly reinforced during the arterial phase of the enhanced CT scan. Upon MRI, the lesion exhibited a low signal on T1-weighted imaging, and a slightly high signal on T2-weighted and half-Fourier acquisition single-shot turbo spin echo sequence imaging, which measured ~4.5x3.0x3.0 cm in size. Upon diffusion-weighted imaging, the lesion demonstrated heterogeneous hyperintensity, which was mildly enhanced during the arterial phase and washed out during the portal venous phase of gadopentetate dimeglumine-enhanced MRI.18 F-fludeoxyglucose ( 18 F-FDG) positron emission tomography (PET)-CT identified a mild uptake of 18 F-FDG by the lesion. The patient was diagnosed with glucagonoma syndrome, and a distal pancreatectomy and splenectomy were subsequently performed. Microscopy revealed that the tumour cells exhibited nest-and belt-like arrangements. The immunohistochemical staining identified positive reactions for glucagon, synaptophysin and chromogranin A, which are consistent with a diagnosis of glucagonoma. Following surgery, the symptoms disappeared and the glucagon level returned to normal. In conclusion, imaging examinations are useful for determining the location and size of a glucagonoma.In particular, MRI is able to identify the distinctive morphological features of the lesion. Immunohistochemical staining provides diagnostic evidence based upon the neuroendocrine features. IntroductionGlucagonoma is an extremely rare neuroendocrine tumour that accounts for 1% of neuroendocrine tumours and <5% of all primary pancreatic malignancies (1,2). Although glucagonoma may appear as a benign neoplasia, at least 50% of glucagonomas cause metastatic disease when diagnosed (2). If the disorder is complicated with systemic clinical manifestations, including necrolytic migratory erythema, hyperglucagonaemia, diabetes mellitus, anaemia, weight loss, glossitis, cheilitis, steatorrhoea, diarrhoea, venous thrombosis and neuropsychiatric disturbances, it is referred to as glucagonoma syndrome (3). At present, the standard treatment for glucagonoma syndrome is surgical resection (2). The early and accurate diagnosis of this syndrome may lead to positive treatment outcomes and an improved prognosis. However, few studies have detailed the imaging features of glucagonoma (4). In particular, the magnetic resonance imaging (MRI) features of the lesion have not yet been reported. A male with glucagonoma syndrome was admitted to the Firs...

Glucagonoma syndrome: a review and update on treatment

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“…The imaging diagnostic methods, including ultrasonograhpy, CT, and MRI, are commonly used. [9] CT scan plays a critical role in assessing location, infiltration, and metastasis of the tumor. In this case, CT showed a pancreatic mass.…”

Malignant transformation of glucagonoma with SPECT/CT In-111 OctreoScan features

“…[ 16 , 17 ] Ultrasonography is not specific nor sensitive and has a low negative predictive value. [ 18 ] The most frequent anatomical site is distal part of the pancreas (90% body and tail) making the US identification even more difficult. [ 9 , 19 ] Tumor presence and localization is invariably documented by CT scan.…”