胰高血糖素瘤综合征表现为一种极为罕见的神经内分泌肿瘤,很少有研究详细介绍其影像学表现。特别是,尚未报道病变的磁共振成像(MRI)特征。本研究描述了一名54岁的男性,他出现了无法控制的皮肤红斑和体重减轻,这已经明显了两年,和糖尿病已经出现了五年。胰高血糖素水平为180pg/ml。普通腹部计算机断层扫描(CT)扫描显示胰腺颈部有实体瘤,在增强CT扫描的动脉阶段略有增强。核磁共振成像,病变在T1加权成像上显示低信号,以及在T2加权和半傅立叶采集单发涡轮自旋回波序列成像上的稍高信号,尺寸约4.5×3.0×3.0厘米。经弥散加权成像,病变表现出不均匀的高强度,在动脉期轻度增强,并在gadopentate二甲葡胺增强MRI的门静脉期洗脱。18F-氟脱氧葡萄糖(18F-FDG)正电子发射断层扫描(PET)-CT鉴定了病变对18F-FDG的轻度摄取。病人被诊断为胰高血糖素综合征,随后进行了远端胰腺切除术和脾切除术。显微镜检查显示,肿瘤细胞表现出巢状和带状排列。免疫组织化学染色确定胰高血糖素呈阳性反应,突触素和嗜铬粒蛋白A,这与胰高血糖素瘤的诊断一致。手术后,症状消失,胰高血糖素水平恢复正常。总之,影像学检查可用于确定胰高血糖素瘤的位置和大小。特别是,MRI能够识别病变的独特形态特征。免疫组织化学染色提供了基于神经内分泌特征的诊断证据。
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 ~4.5×3.0×3.0 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. 18F-fludeoxyglucose (18F-FDG) positron emission tomography (PET)-CT identified a mild uptake of 18F-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.