儿童胰母细胞瘤的CT和MRI特点

CT and MR imaging characteristics of pancreatoblastoma in children

目的:探讨儿童胰母细胞瘤的CT及MRI特征。方法:回顾性分析经手术或活检病理证实的14例胰母细胞瘤的术前CT及MRI资料。14例患儿中,9例行CT平扫、增强检查,3例行CT平扫、增强检查和MR平扫、增强检查,1例行CT平扫、增强和MRI平扫检查,1例行MRI平扫、增强扫描。MRI检查病例中,3例同时行DWI检查。结果:肿块大小4.0～14.6 cm,平均约8.4 cm。6例(6/14,占42.9%)位于胰腺体尾部,5例(5/14,占35.7%)位于胰头部,3例(3/14,占21.4%)位于胰尾部。4例(4/14,占28.6%)呈分叶状,9例(9/14,占64.3%)呈类椭圆形,1例(1/14,占7.1%)呈葫芦形。所有肿瘤均表现为边界清或不清的不均质肿块,伴囊变及(或)坏死,4例囊变及(或)坏死区域显著,超过肿瘤体积50%,其中1例囊变坏死区域大于90%。增强后肿块均呈不均匀强化,9例(64.3%)伴包膜或部分包膜样强化,9例(64.3%)病灶内及(或)周边区域可见小血管。肿块内出血3例(3/14,占21.4%),13例行CT检查的病例中8例(8/13,占61.5%)伴有钙化。4例胰管扩张,其中2例合并胆管扩张。14例中10例(10/14,占71.4%)侵犯周围血管;6例(6/14,占42.9%)发生远处转移,其中肝转移4例,肝、骨转移1例,肺转移1例。3例行DWI检查的病灶实性区域均呈高信号,最大横截面实性成分的ADC平均值为884.2×10^(-3)mm^2/s。结论:胰母细胞瘤具有体积较大,肿瘤内钙化囊变、坏死多见及增强后呈不均匀强化特点,易侵犯周围脏器、血管及发生血行转移和淋巴转移。

Objective:To explore the CT and MR imaging features of pancreatoblastoma in children.Methods:CT and MRI manifestations of 14 cases with pancreatoblastoma proved by surgery and pathology were analyzed retrospectively.9 cases underwent pre-and post-contrast enhanced CT scan,3 cases underwent pre-and post-contrast enhanced CT and MR scan,1 case underwent pre-and post-contrast CT scan and plain MR scan,1 case underwent pre-and post-contrast enhanced MR scan.Of the cases examined by MRI,3 underwent DWI examination at the same time.Results:The size of the tumors ranged from 4.0cm to 14.6cm,average 8.4cm.6 cases(6/14,42.9%)were located at the pancreatic body and tail,5 cases(5/14,35.7%)at the head of pancreas,3 cases(3/14,21.4%)at the tail;4 cases(4/14,28.6%)were lobulated in shape,9 cases(9/14,64.3%)were oval,1 case(1/14,7.1%)showed gourd shape.All tumors were characterized by clear or unclear contour and giant heterogeneous masses with cystic degeneration or necrosis,and 4 cases had prominent cystoid variation and(or)necrosis with the necrotic area more than 50%of the tumor volume(1 case more than 90%).All cases demonstrated heterogeneous enhancement.Partial or whole ring-shaped capsular enhancement was noted in 9 cases(64.3%).Small intra-lesional vessels were seen in 9 cases(64.3%).Bleeding signals were detect in 3 cases(3/14,21.4%).Of the 13 cases with CT examination,calcifications were found in 8 cases(8/13,61.5%).Dilatation of pancreatic main duct was found in 4 cases,of which 2 cases were combined with bile duct dilatation.Of the 14 cases,10 cases(10/14,71.4%)invaded peripheral blood vessels.6 cases(6/14,42.9%)had distance distant metastasis including 4 cases had liver metastasis,1 case had bone and liver metastasis,and 1 case had lung metastasis respectively.3 cases with DWI examination showed restricted diffusion high signals in the solid region of the lesion.The average ADC value across the largest sectional solid component was 884.2×10-3 mm 2/s.Conclusion:Pancreatoblastomas were usually large at presentation.Calcification was common,with varying degrees of cystic degeneration and central necrosis,the areas of cystic components and necrosis might exceed 50%.After intravenous contrast administration,tumor was typically heterogeneously enhanced with small vessels in and/or around the tumors.Nearby and distant invasion of adjacent structures often occur and was often associated with distant and lymph node metastases.