原发性纵隔绒毛膜癌（PCC）是一种罕见的、高度血管侵袭性且预后不良的恶性肿瘤。当发生在性腺之外时，原发性绒毛膜癌通常发现于中线位置，例如纵隔或腹膜后。目前，PCC尚无标准化的治疗策略。在本文报道的病例中，我们采用替雷利珠单抗和化疗治疗一名 PCC 患者，截至 2024 年 3 月，该患者仍然存活。 一名 15 岁男孩，出现发烧和咳嗽症状一年。胸部计算机断层扫描（CT）显示右上前纵隔有一较大软组织影，尺寸约为5.4 cm×3.8 cm。患者软组织与周围纵隔结构分界不清，并伴有肺转移。患者对纵隔肿块进行细针抽吸活检，病理结果显示纵隔内存在生殖细胞瘤，并伴有实体恶性成分，且实体恶性肿瘤肺转移。患者血清β-人绒毛膜促性腺激素（β-HCG）水平升高至125,554 mIU/mL（正常范围：<5 mIU/mL），甲胎蛋白（AFP）为75.8 ng/mL（正常范围：0.605 -7纳克/毫升）。患者的头颅磁共振成像（MRI）平扫显示两个大脑半球存在多个分散的异常信号。随后，患者被转至南京医科大学附属儿童医院进一步治疗。在治疗期间，我们采用了多种治疗方法，包括化疗、放疗和替雷利珠单抗治疗。经过5个周期的替雷利珠单抗治疗后，患者脑水肿症状明显改善，β-HCG水平下降。患者的脑部核磁共振显示颅骨内存在多个异常信号，部分病灶显示尺寸缩小，周围水肿区明显改善。患者临床症状改善，达到部分缓解（PR）。目前，患者仍与疾病共存。化疗对PCC的疗效有限。替雷利珠单抗可能作为 PCC.2024 转化儿科的挽救治疗选择。版权所有。

Primary mediastinal choriocarcinoma (PCC) is a rare, highly vascular invasive, and prognostically unfavorable malignant tumor. When occurring outside the gonads, primary choriocarcinoma is commonly found in midline locations such as the mediastinum or retroperitoneum. Currently, there is no standardized treatment strategy for PCC. In the case reported herein, we employed tislelizumab and chemotherapy in the treatment of a patient with PCC, and as in March 2024, the patient remained survive.A 15-year-old boy who presented with symptoms of fever and cough for a year. Chest computed tomography (CT) scan showed a relatively large soft tissue shadow in the right upper anterior mediastinum, measuring approximately 5.4 cm × 3.8 cm. The patient's soft tissue exhibited unclear demarcation from surrounding mediastinal structures and was accompanied by lung metastasis. The patient underwent a fine needle aspiration biopsy for a mediastinal mass, and the pathology results indicated a germ cell tumor with solid malignant components in the mediastinum, along with pulmonary metastasis of the solid malignancy. The patient's serum levels of beta-human chorionic gonadotropin (β-HCG) were elevated at 125,554 mIU/mL (normal range: <5 mIU/mL), and alpha-fetoprotein (AFP) was 75.8 ng/mL (normal range, 0.605-7 ng/mL). The patient's cranial magnetic resonance imaging (MRI) plain scan indicated multiple scattered abnormal signals in both cerebral hemispheres. Subsequently, the patient was transferred to Children's Hospital of Nanjing Medical University for his further treatment. During the treatment period, we employed various therapeutic approaches, including chemotherapy, radiotherapy and tislelizumab therapy. After five cycles of tislelizumab treatment, the patient's symptoms of cerebral edema significantly improved, β-HCG levels decreased. Brain MRI of the patient revealed multiple abnormal signals within the skull, with some lesions showing reduction in size and significant improvement in the surrounding edema zones. The clinical symptoms of the patient improved and he achieved partial remission (PR). At the moment, the patient is living with the disease.The effectiveness of chemotherapy for PCC is limited. Tislelizumab may potentially serve as salvage treatment options for PCC.2024 Translational Pediatrics. All rights reserved.