不典型脉络丛乳头状瘤1例：临床及病理研究

目的探讨不典型脉络丛乳头状瘤的临床特点、病理诊断及鉴别诊断。方法分析1例4岁男性不典型脉络丛乳头状瘤病人的临床资料，光镜下观察病理形态特征并行免疫组化研究。结果CT显示右侧颞叶脑实质占位。MRI显示右侧侧脑室囊实性占位。病理形态多样，部分区域分化差，细胞密度增加、核分裂3-5个／10HPF，呈片状方式生长。免疫组化结果：角蛋白（CK）、波形蛋白（Vimentin）阳性，上皮膜抗原（EMA）弱阳性；S-100、胶质纤维酸性蛋白（GFAP）等均为阴性。Ki-67阳性率局部〉5％。结论病人年龄、肿瘤准确定位等临床资料对病理诊断较为重要；严格掌握肿瘤的诊断标准并辅以合理的免疫组化检查，对诊断与鉴别诊断极为重要。

Atypical choroid plexus papilloma (WHO 2007):report of 1 case

Objective To study the clinical features, pathological diagnosis and differential diagnoses of atypical choroid plexus papilloma. Methods Clinical data of a four-year-old boy with atypical choroid plexus papilloma were analyzed clinically. The morphological characteristics were observed by light microscope and immunohistochemistry. Results The patient presented with headache accompanied by nausea and vomiting. CT scan indicated a tumor mass in the right temporal lobe of brain parenchyma. The tumor appeared as a cyst-like solid mass and located in the right lateral ventricle on MRI. Histopathological feature was morphological variety with well-differentiated part and poor-differentiated areas, the latter showed malignant morphological features of choroid plexus tumor, including increased cellular density, sheet-like growth of tumor cells and brisk mitotic activity （3-5/10 HPF）. Immunohistochemically, tumor cells expressed cytokeratin （CK） and Vimentin, and weakly positive for epithelial membrane antigen （EMA）. Immunohistochemical staining were negative for S-100 protein, glial fibrillary acidicprotein （GFAP） and other markers. The Ki-67 labeling-positive tumor cells were more than 5% locally. Conclusion Clinical data, such as age of the patient and the accurate location of the tumor are essential for the final diagnosis. Strictly controlling the diagnosis criterion of atypical choroid plexus papilloma and reasonable application of immunohistochemistry are extremely important for the pathological diagnosis and differential diagnoses.