2例婴幼儿胰母细胞瘤临床病理分析

Clinicopathological study on pancreatoblastoma in 2 cases of infants

目的:探讨婴幼儿胰母细胞瘤(pancreatoblastoma,PBL)的临床病理特征以及诊断与鉴别诊断。方法:回顾分析2例PBL患儿的临床资料、病理学特征、免疫组织化学结果,并复习相关文献。结果:2例PBL患儿均为无意中发现腹部肿块。组织学可见肿瘤细胞由上皮和数量不等的间质组成,密集的上皮被纤维间质分隔,形成巢状或器官样结构。肿瘤显示腺泡、导管和片状排列,排列成片状的瘤细胞中可见特征性的鳞状上皮岛。免疫组织化学结果显示2例角蛋白均阳性表达,抗胰糜蛋白酶局灶性阳性;嗜铬粒素A、神经元特异性烯醇化酶及CD99各1例局灶性阳性;2例导管分化的细胞癌胚抗原阳性表达;甲胎蛋白和突触素均阴性。结论:PBL是一种罕见的胰腺低度恶性肿瘤,多发生于婴幼儿。鳞状上皮岛为其组织学特征性改变,在诊断时应与其他胰腺肿瘤及畸胎瘤鉴别。

Objective： To determine the clinical pathological features, pathological diagnosis, and differential diagnosis of the pancreatoblastoma （PBL） in infants. Methods： Pathological and immunohistochemical observations were conducted in 2 infants with PBL, and their clinical data and literature were analyzed and reviewed, respectively. Results： These 2 infants showed a feature of abdominal mass. Microscopic findings revealed that the tumors were composed of epithelial cells with amount of stroma. The epithelial cells were separated by fiber stromal tissues, forming nest or organoid patterns. The tumors exhibited acini, short tubules and solid islands. The tumor cells in the solid islands formed squamoid nests. Immunohistochemical results showed that the tumor cells were positive for cytokeratin （n=2）, α-1-antichymotrypsin（AACT）（n=2）, neuron specific endolase （n=l）, chromogranin A （n=l）, CD99 （n=1）, and carcinoembryonic antigen （n=2）, but negative for synaptophysin and alpha-fetoprotein. Conclusion： PBL is a rare lower grade pancreatic malignant tumor and often occurs in infants. The squamoid nest is the characteristic of PBL, which should be differentiated from the other pancreatic neoplasms and teratoma.