Center for Comprehensive Cancer Care, 4117 Veterans Memorial Drive, Mount Vernon, IL 62864, USA.
Expert Rev Hematol. 2012 Aug;5(4):427-37. doi: 10.1586/ehm.12.24.
Germ cell tumor (GCT)-associated hematologic malignancies present a unique challenge to hematologists and hematopathologists. As most GCTs are of gonadal origin, only a small percentage occur at extragonadal sites in the midline. Extragonadal GCTs are believed to originate from the ectopic primordial germ cells that fail to migrate to the urogenital ridge during development. An overactive KIT pathway and overexpression of genes on chromosome 12p are strongly implicated in GCT development. Approximately 54% of extragonadal GCTs are located in the anterior mediastinum. This is disproportionally high among the midline structures, presumably due to a favorable microenvironment for GCT development in the developing thymus. The mediastinal nonseminomatous GCTs have two unique features. First, they are often refractory to current treatment modality with the worst prognosis among GCTs of all sites. Second, they have a tendency to give rise to secondary hematologic neoplasia. The outcome is grave for patients with GCT-associated hematologic malignancies. As standard chemotherapy used to treat their bone marrow-derived counterparts has been ineffective, the best treatment modality to achieve long-term survival is allogeneic hematopoietic stem cell or cord blood transplant for a very limited number of cases.
生殖细胞肿瘤（GCT）相关血液病对血液学家和血液病理学家提出了独特的挑战。由于大多数 GCT 来源于性腺，只有一小部分发生在中线的性腺外部位。性腺外 GCT 被认为起源于在发育过程中未能迁移到尿生殖嵴的异位原始生殖细胞。KIT 通路的过度活跃和 12p 染色体上基因的过度表达强烈提示 GCT 的发生。约 54%的性腺外 GCT 位于前纵隔。这在中线结构中不成比例地高，可能是由于在发育中的胸腺中存在有利于 GCT 发生的微环境。纵隔非精原细胞瘤 GCT 具有两个独特的特征。首先，它们通常对当前的治疗模式具有抗药性，是所有部位 GCT 中预后最差的。其次，它们有发展为继发性血液病的倾向。对于患有 GCT 相关血液病的患者，预后是严重的。由于用于治疗其骨髓来源的对应物的标准化疗无效，对于极少数病例，实现长期生存的最佳治疗模式是同种异体造血干细胞或脐带血移植。
