Zec N, De Girolami U, Schofield D E, Scott R M, Anthony D C
Department of Pathology (Neuropathology), Children's Hospital, Boston, MA 02115, USA.
Am J Surg Pathol. 1996 Sep;20(9):1091-101. doi: 10.1097/00000478-199609000-00007.
We describe two histologically unusual cases of ependymoma of the filum terminale. Both tumors occurred in 14-year-old boys. An intradural encapsulated mass attached to the filum terminale was demonstrated radiologically in both cases and totally resected at surgery. In case 1 the neoplasm was uniformly composed of pleomorphic giant cells and was without perivascular pseudorosettes or myxopapillary changes. Case 2 was a myxopapillary ependymoma with multiple foci of pleomorphic giant cells. Neither tumor had prominent mitotic activity, necrosis, or endothelial proliferation. Both tumors were immunopositive for cytokeratin and glial fibrillary acidic protein. Ultrastructural features included basal laminae, interdigitating cell processes, microvilli, cilia, intercellular junctions, and cytoplasmic intermediate filaments. Cytogenetic analysis in case 1 showed a hypodiploid karyotype with monosomy of chromosomes 1, 10, 14, 16, 20, and 22. We interpret both tumors as most consistent with a variant of ependymoma. Because of the unique gigantocellular light microscopic appearance of the entire tumor in case 1, we propose classifying this tumor as a new morphologic subtype: giant cell ependymoma of the filum terminale. The combination of gigantocellular and myxopapillary features in case 2 supports a histogenetic relationship between giant cell ependymoma and myxopapillary ependymoma.
我们描述了两例组织学上不寻常的终丝室管膜瘤病例。两例肿瘤均发生于14岁男孩。影像学检查显示两例病例均有硬膜内包块附着于终丝，并在手术中完全切除。病例1中肿瘤由多形性巨细胞均匀组成，无血管周围假菊形团或黏液乳头样改变。病例2为黏液乳头型室管膜瘤，伴有多个多形性巨细胞灶。两例肿瘤均无明显的有丝分裂活性、坏死或内皮细胞增生。两例肿瘤细胞角蛋白和胶质纤维酸性蛋白免疫染色均呈阳性。超微结构特征包括基膜、指状细胞突起、微绒毛、纤毛、细胞间连接和细胞质中间丝。病例1的细胞遗传学分析显示为亚二倍体核型，染色体1、10、14、16、20和22单体。我们认为这两例肿瘤最符合室管膜瘤的一种变异型。由于病例1中整个肿瘤独特的巨细胞光镜表现，我们建议将该肿瘤分类为一种新的形态学亚型：终丝巨细胞室管膜瘤。病例2中巨细胞和黏液乳头特征的组合支持了巨细胞室管膜瘤和黏液乳头型室管膜瘤之间的组织发生学关系。
