White F V, Anthony D C, Yunis E J, Tarbell N J, Scott R M, Schofield D E
Department of Pathology, Children's Hospital of Boston, MA 02115, USA.
Hum Pathol. 1995 Sep;26(9):979-86. doi: 10.1016/0046-8177(95)90087-x.
Low-grade astrocytomas are the most common central nervous system (CNS) tumor occurring in the pediatric age group. Although many of these tumors are karyotypically normal, various studies have reported gains of chromosomes in a significant proportion of cases. We have the opportunity to karyotype two pilocytic astrocytomas occurring in 5- and 15-year-old children. These tumors were characterized by stemlines of 49,XY,+4,+7,+8 and 48,XX,+7,+8. Using these patients as index cases and based on additional karyotypic data that have been published, we performed fluorescence in situ hybridization on 25 additional cases of low-grade astrocytomas in children using pericentromeric probes for chromosomes 4, 6, 7, 8, 9, 10, 11, 12, 15, and 17. Six of 18 (excluding the two index cases), or one third, of the pilocytic astrocytomas were characterized by chromosomal gains, most commonly chromosomes 7 and 8, suggesting that trisomy 7 and 8 are relatively common events in the tumorigenesis of pilocytic astrocytomas. In contrast, chromosomal trisomies were not detected in seven well-differentiated fibrillary astrocytomas with any of the probes chosen.
低级别星形细胞瘤是小儿年龄组中最常见的中枢神经系统（CNS）肿瘤。尽管这些肿瘤中的许多在核型上是正常的，但各种研究报告称，在相当比例的病例中存在染色体增加。我们有机会对两名分别发生在5岁和15岁儿童身上的毛细胞型星形细胞瘤进行核型分析。这些肿瘤的特征性干系分别为49,XY,+4,+7,+8和48,XX,+7,+8。以这些患者作为索引病例，并基于已发表的其他核型数据，我们使用针对染色体4、6、7、8、9、10、11、- 12、15和17的着丝粒探针，对另外25例儿童低级别星形细胞瘤进行了荧光原位杂交。18例（不包括两名索引病例）毛细胞型星形细胞瘤中有6例，即三分之一，表现为染色体增加，最常见的是染色体7和8，这表明三体7和8在毛细胞型星形细胞瘤的肿瘤发生中是相对常见的事件。相比之下，在7例分化良好的纤维型星形细胞瘤中，使用所选择的任何探针均未检测到染色体三体。
