Abstract:
Somatic malignant transformation of germ cell tumours is a well-described but poorly understood phenomenon. It is characterized by differentiation of pluripotent teratoma cells into somatic tumour cells. Following malignant transformation, the most common histologies are sarcomas and primitive neuroectodermal tumours; however, other subtypes have been recognized including melanoma, leukaemia, and renal cell carcinoma. We report a case of a 38-year-old male who had recently completed treatment for a mediastinal germ cell tumour with teratomatous components. He presented several months after completion of chemotherapy with metastatic lesions in his spine and liver accompanied with severe pancytopenia. He was subsequently diagnosed with acute megakaryoblastic leukaemia (AMKL), and a biopsy of a liver lesion was consistent with metastatic melanoma. This case illustrates the simultaneous development of 2 rare malignant entities: mediastinal germ cell tumour-associated AMKL and somatic malignant transformation to melanoma. It also highlights the importance of close surveillance to detect these metastatic sequelae and the emerging role of tumour sequencing to establish targetable pathways.
摘要:
生殖细胞肿瘤的体细胞恶性转化是一个描述良好但知之甚少的现象。其特征在于多能畸胎瘤细胞分化成体细胞肿瘤细胞。恶性转化后,最常见的组织学是肉瘤和原始神经外胚层肿瘤;然而,其他亚型已经被识别,包括黑色素瘤,白血病,和肾细胞癌。我们报告了一例38岁的男性,他最近完成了对具有畸胎瘤成分的纵隔生殖细胞肿瘤的治疗。他在完成化疗几个月后出现脊柱和肝脏转移性病变,并伴有严重的全血细胞减少症。他随后被诊断患有急性巨核细胞白血病(AMKL),肝损伤活检与转移性黑色素瘤一致。此病例说明了两种罕见的恶性实体的同时发展:纵隔生殖细胞肿瘤相关的AMKL和向黑色素瘤的体细胞恶性转化。它还强调了密切监测以检测这些转移性后遗症的重要性,以及肿瘤测序对建立可靶向途径的新兴作用。