Rao U N, Surti U, Hoffner L, Yaw K
Department of Pathology, University of Pittsburgh Medical Center, Pennsylvania, 15213-2582, USA.
Cancer Genet Cytogenet. 1996 May;88(1):17-25. doi: 10.1016/0165-4608(95)00281-2.
Cytogenetic analysis was performed on 11 peripheral nerve sheath tumors of soft tissue from 10 patients. They include 6 benign and 5 malignant schwannomas. Five cases which include two benign, one cellular and two malignant schwannomas had a known association with a nerve, but only one patient with malignant schwannoma has clinically documented neurofibromatosis type I. All the patients had a normal diploid constitutional karyotype. Two cases of cellular schwannoma were analyzed by routine cytogenetic analysis and fluorescence in situ hybridization (FISH). One tumor was karyotyped as 45, XX,-13,-22 +mar; and the other case had a 45,X,-Y,t(1;17) (p12;q11.2) karyotype. In the latter, the breakpoint in 17q occurred below the centromere and is at or in the region of the Neurofibromatosis Type 1 (NF1) gene. Four benign tumors had a normal diploid karyotype. One hypodiploid malignant schwannoma with myxoid features demonstrated monosomy of chromosomes 17 and 22 by FISH analysis. The rest of the malignant schwannomas showed a wide range of numerical and structural aberrations, with frequent loss of 22q and gains of chromosomes 2 and 7. Loss of a sex chromosome was observed in cellular as well as malignant schwannomas. Regional karyotypic evolution was noted in one malignant schwannoma. Cytogenetic analysis may prove to be useful in identifying tumors, such as cellular schwannomas, which, because of their histologic features may be inadvertently categorized as malignant. Simultaneous involvement of NF1 and NF2 genes, which are located on chromosomes 17q and 22q, respectively, should be investigated at a molecular level in both benign and malignant tumors of peripheral nerves.
对10例患者的11个软组织周围神经鞘瘤进行了细胞遗传学分析。其中包括6例良性和5例恶性神经鞘瘤。5例（包括2例良性、1例细胞型和2例恶性神经鞘瘤）与神经有已知关联，但只有1例恶性神经鞘瘤患者有临床记录的Ⅰ型神经纤维瘤病。所有患者的二倍体体质核型均正常。对2例细胞型神经鞘瘤进行了常规细胞遗传学分析和荧光原位杂交（FISH）。1例肿瘤核型为45,XX,-13,-22 +mar；另一例核型为45,X,-Y,t(1;17)(p12;q11.2)。在后者中，17q的断点发生在着丝粒下方，位于神经纤维瘤病1型（NF1）基因区域或该区域内。4例良性肿瘤核型正常。1例具有黏液样特征的亚二倍体恶性神经鞘瘤经FISH分析显示17号和22号染色体单体性。其余恶性神经鞘瘤显示出广泛的数目和结构异常，常见22q缺失和2号及7号染色体增加。在细胞型和恶性神经鞘瘤中均观察到性染色体丢失。在1例恶性神经鞘瘤中发现了区域核型演变。细胞遗传学分析可能有助于识别某些肿瘤，如细胞型神经鞘瘤，因其组织学特征可能被误分类为恶性。对于周围神经的良性和恶性肿瘤，应在分子水平上研究分别位于17q和22q染色体上的NF1和NF2基因的同时受累情况。
