胰腺内副脾伴表皮样囊肿的影像特征

The imaging features of epidermoid cyst within intrapancreatic accessory spleen

目的探讨胰腺内副脾伴表皮样囊肿(ECIPAS)的影像学特征。方法回顾性分析2015年9月至2018年4月复旦大学附属肿瘤医院7例经病理证实的ECIPAS患者资料。7例均行腹部CT平扫及增强扫描,2例患者行MR胰胆管成像(MRCP)检查,5例同时行腹部超声检查。分析其影像特征。结果CT扫描示5例病灶位于胰尾部,2例位于胰颈部。病灶最大径1.5~4.8cm,平均(2.8±1.2)cm。2例病灶表现为多房性囊肿。CT平扫2例表现为境界清楚的低密度灶,2例表现为稍高密度结节,2例可见钙化;增强后4例环绕囊肿的实质呈渐进性强化,动脉期和静脉期实质成分的强化程度较脾脏相似且高于胰腺组织。MRCP检查2例均未见囊肿与胰管相通,胰胆管均无扩张,其中1例表现为胰颈体部后方类圆形稍高信号影。超声检查5例病灶表现为境界欠清的无回声或低回声,形态不规则。结论发病部位除了胰尾也可见于胰颈部,影像表现为囊肿周边包绕强化程度与脾脏相似且高于胰腺的副脾组织,强化方式呈渐进性。

Objective To investigate the imaging features of epidermoid cyst within intrapancreatic accessory spleen (ECIPAS) to make benefits for differential diagnosis of pancreatic lesions. Methods We retrospectively reviewed the clinicalradiological and pathological data of 7 patients with pathologically confirmed ECIPAS.All the cases underwent plain and contrast enhanced CT scan,2 cases underwent magnetic resonance cholangiopancreatography (MRCP), and 5 cases underwent ultrasonic examination. The imaging features of the lesions were analyzed. Results CT showed that 5 lesions were situated in the pancreatic tail while the other two located in the neck.The mean size of the lesions was (2.8±1.2) cm,ranging from 1.5 to 4.8 cm. The cysts appeared multiocular in 2 cases. On plain CT, 2 cases showed well-defined low density foci, while 2 cases showed slightly high density. Calcification can be found in 2 cases. In 4 cases, the solid component surrounding the cyst displayed progressive enhancement on postcontrast CT. The enhancement was higher than the pancreatic parenchymaand similar to the spleen during both arterial and portal venous phases. On MRCP,no expansion was shown in pancreatic duct andit had no relationship with cyst in both 2 cases while slightly hypointensity could be found at the back and it pancreatic neck and body in 1 case. Five lesions were hypoechoic or anechoic and irregular-shaped on ultrasound. Conclusion ECIPAS is a rare benign lesion and the typical imaging manifestation is a cyst with surrounding solid component with enhancement similar to the spleen while higher than pancreas.