Objective: To investigate the clinicopathological features of children with metachronous or synchronous primary tumors and to identify related genetic tumor syndromes. Methods: The clinicopathological data of 4 children with multiple primary tumors diagnosed in the Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China from 2011 to 2023 were collected. The histological, immunophenotypic and molecular characteristics were examined using H&E staining, immunohistochemical staining, PCR, Sanger sequencing and next-generation sequencing (NGS). The patients were followed up. Results: Case 1 was an 8-year-old boy with the adrenal cortical carcinoma, and 5 years later a poorly differentiated gastric adenocarcinoma was detected. Case 2 was a 2-year-old boy, presented with a left ventricular choroid plexus carcinoma, and a hepatoblastoma was detected 8 months later. Case 3 was a 9-month-old girl, diagnosed with renal rhabdoid tumor first and intracranial atypical teratoid/rhabdoid tumor (AT/RT) 3 months later. Case 4 was a 7-year-old boy and had a sigmoid colon adenocarcinoma 3 years after the diagnosis of a glioblastoma. The morphology and immunohistochemical features of the metachronous or synchronous primary tumors in the 4 cases were similar to the corresponding symptom-presenting/first-diagnosed tumors. No characteristic germ line mutations were detected in cases 1 and 2 by relevant molecular detection, and the rhabdoid tumor predisposition syndrome was confirmed in case 3 using NGS. Case 4 was clearly related to constitutional mismatch repair deficiency as shown by the molecular testing and clinical features. Conclusions: Childhood multiple primary tumors are a rare disease with histological morphology and immunophenotype similar to the symptom-presenting tumors. They are either sporadic or associated with a genetic (tumor) syndrome. The development of both tumors can occur simultaneously (synchronously) or at different times (metachronously). Early identification of the children associated with genetic tumor syndromes can facilitate routine tumor screening and early treatment.
目的： 探讨儿童多原发肿瘤的临床病理学特征及识别相关遗传肿瘤综合征。 方法： 收集上海交通大学医学院附属新华医院病理科2011—2023年诊断的4例儿童多原发肿瘤患者的临床病理资料，采用HE染色、免疫组织化学染色、PCR、Sanger测序及二代测序等方法观察组织学、免疫表型以及分子特征，并随访患者。 结果： 例1男，8岁，首发肾上腺皮质癌，5年后检出胃低分化腺癌；例2男，2岁，首发左侧侧脑室脉络丛癌，8个月后检出肝母细胞瘤；例3女，9个月，首发肾脏横纹肌样瘤，3个月后发现颅内非典型畸胎样/横纹肌样瘤；例4男，7岁，首发胶质母细胞瘤，3年后检出乙状结肠腺癌。4例患儿多原发肿瘤形态学及免疫组织化学均与相应的单发肿瘤相似，例1和例2经相关分子检测未检出特征性种系突变，例3经二代测序检测证实为横纹肌样瘤易感综合征，例4结合分子检测及临床特征明确与体质错配修复缺陷相关。 结论： 儿童多原发肿瘤是一类罕见的疾病，组织学形态和免疫表型与散发肿瘤相似，或散发，或与遗传肿瘤综合征相关。两种肿瘤可同时或异时发生，及早识别与遗传肿瘤综合征有关的患儿有助于实施定期肿瘤筛查并得到及时治疗。.