非良性胰腺导管内乳头状黏液瘤计算机断层摄影特征

Imaging Features of Computed Tomography of Non-benign Intraductal Papillary Mucinous Neoplasm of Pancreas

目的探讨非良性胰腺导管内乳头状黏液瘤(intraductal papillary mucinous neoplasm,IPMN)计算机断层摄影(computed tomography,CT)典型影像学表现,分析IPMN影像与病理表现的一致性。方法回顾性分析2008年5月至2011年2月本院收治的12例经手术病理证实为交界性胰腺IPMN或胰腺导管内乳头状黏液癌(intraducted papillary mucinous carcinoma,IPMC)患者的术前CT影像(腹平扫+增强+三维重建),并与其术后病理结果进行对照。结果术后病理证实的12例非良性胰腺IPMN患者中4例为交界性IPMN,2例为非浸润性IPMC,6例为浸润性IPMC。IPMN患者临床表现腹痛无特异性,而体重减轻、黄疸和糖尿病主要见于浸润性IPMC。恶性IPMN的CT分型多为主胰管型(3例)或混合型(4例),分支胰管型较少(1例)。IPMN患者常见CT表现包括胰腺内囊性病变形成、胰管扩张、胰腺钙化、实质萎缩等,其中囊内密度增高和壁结节等在交界性病变和恶性病变中均存在,胰管扩张程度与病变恶性程度呈正相关,而壁结节直径与病变恶性程度无明显相关性。恶性病变囊内容物的CT值一般高于交界性病变,且多表现为不均匀高密度。浸润性IPMC患者中50%有周围组织受累,其CT表现和病理结果完全吻合。CT显示胆总管明显增宽的病变仅见于浸润性IPMC患者。结论多排螺旋CT对非良性胰腺IPMN的术前诊断价值较高,与病理结果的相关性较好,对于IPMN病变恶性程度预测及周围组织受累判断的准确度较高,可为临床诊断和手术方式选择提供良好的支持。

Objective To evaluate the imaging features of computed tomography （CT） of non-benign intraductal papillary mucinous neoplasm （IPMN） of pancreas, and to explore the correlation between radiological and pathological finding. Methods CT images of 12 patients who were pathologically diagnosed as non-benign IPMN of pancreas between May, 2008 and February, 2011 in Peking Union Medical College Hospital were retrospectively evaluated. Their pre-surgery CT images were reviewed by 2 experienced radiologists, and the radio-pathological results were compared to evaluate the diagnostic value of CT techniques. Results Of these 12 patients, 4 were pathologically proved as borderline IPMN, 2 as non-invasive intraductal papillary mucinous carcinoma （IPMC）, and 6 as invasive IPMC. The clinical manifestations including weight loss, jaundice and diabetes suggested malignancy, while abdominal discomfort or pain has no specificity. IPMN were divided into 3 types according to CT classification, namely main pancreatic duct type, branch pancreatic duct type and mixed type. The branch duct type were rarely seen in malignant IPMN cases. The common radiological features of IPMN included pancreatic duct dilation or large cysts formation （with septa or focal nodules inside）, pancreatic parenchymal calcification and atropy, which were seen in both borderline IPMN and IPMC. However, for malignant cases, the pancreatic duct dilation were much severer; CT values in the dilated pancreatic ducts were higher, and showed a heterogeneity within the duct. Common bile duct dilation were seen in invasive IPMC only. Conclusions Multi-slice spiral CT is valuable in the pre-surgery diagnosis of non-benign IPMN, and shows a good agreements with pathological results. The CT features of IPMN lesions can predict the degree of malignancy and the involvement of surrounding tissues at a favorable accuracy, and therefore provides useful information for clinical diagnosis and decision for surgery.