原发性纵隔卵黄囊瘤4例并文献复习

Primary mediastinal yolk sac tumor:a report of 4 cases and review of literature

目的探讨原发性纵隔卵黄囊瘤(PMYST)的临床病理学特征、诊断、鉴别诊断及预后。方法回顾性分析4例纵隔卵黄囊瘤的临床资料、采用HE染色和免疫组化EnVision两步法,分析其临床病理特征并复习国内外相关文献。结果肿瘤呈网状、微囊状结构、内胚窦结构等多种生长方式混合存在,肿瘤细胞核大、空泡状,核仁明显,细胞质内可见嗜酸性透明小体。免疫组化表型:肿瘤细胞不同程度表达SALL4、AE1/AE3、GPC-3、HNF1β,表达或不表达AFP、CD117、PLAP及EMA,不表达CD30、OCT3/4、D2-40,Ki-67指数60%~70%。本组病例及复习文献共48例,随访时间1~144个月,死亡20例,生存曲线显示死亡病例均约在2年内死亡。结论PMYST是一种少见高度恶性生殖细胞肿瘤,好发于中青年男性,2年内死亡率较高,血清中AFP的含量有助于诊断、监测治疗反应和检测肿瘤的复发,治疗上以手术及化疗为主,且化疗敏感。

Objective To investigate the clinicopathological features,diagnosis,differential diagnosis and prognosis of primary mediastinal yolk sac tumors(PMYST).Methods A retrospective analysis of clinical data from four cases of mediastinal yolk sac tumors was performed.HE staining and the immunohistochemical EnVision two-step method were used to analyze the clinicopathological characteristics,and a review of related domestic and international literature was conducted.Results The tumors exhibited a mixture of growth patterns,including reticular,microcystic,and endodermal sinus structures.Tumor cells had large,vacuolated nuclei with prominent nucleoli,and eosinophilic hyaline globules were observed in the cytoplasm.Immunohistochemically tumor cells expressed SALL4,AE1/AE3,GPC-3,and HNF1β,with variable expression of AFP,CD117,PLAP,and EMA,and negative expression of CD30,OCT3/4,and D2-40.The Ki-67 index was 60%-70%.This case series,along with a review of the literature encompassing 48 cases,showed a follow-up period ranging from 1 to 144 months,with 20 deaths.The survival curve indicated that all deaths occurred within approximately 2 years.Conclusion PMYST is a rare and highly malignant germ cell tumor that predominantly affects young and middle-aged men,with a high mortality rate within 2 years.Serum AFP levels are helpful for diagnosis,monitoring therapeutic response,and detecting tumor recurrence.Treatment primarily involves surgery and chemotherapy,with the latter being effective.