性腺外卵黄囊瘤8例临床病理分析

Primary extragonadal yolk sac tumor: a clinicoathologic analysis of 8 cases

目的探讨性腺外卵黄囊瘤的临床病理特征、免疫表型、治疗与预后。方法对8例性腺外卵黄囊瘤的临床资料、病理特点及免疫组化等进行回顾性研究,并复习相关文献。结果本组病例平均年龄4.3岁。临床表现因肿瘤所在的解剖部位。血清AFP明显升高。肿瘤组织形态多样,具有疏松的网状结构、S-D小体和嗜酸性小体等特点。免疫组化显示AFP、SALL4、CK和PLAP（＋）,CD117、EMA、vimentin、p16、CD34和HPL部分（＋）,Oct3/4、Sox-2、HCG、CD30、CA125和WT-1（-）,Ki-67阳性指数1%～90%。预后差。结论性腺外和性腺内卵黄囊瘤的组织学特点类似,但性腺外卵黄囊瘤好发于婴幼儿,且预后更差。血清AFP含量的高低有助于性腺外卵黄囊瘤的诊断。

Objective To investigate the clinicopathologic features,immunophenotype,therapy and prognosis of primary extragonadal yolk sac tumor. Methods Clinical data,pathological and immunohistochemical features were analyzed in eight patients with extragonadal yolk sac tumor. The related literatuers were reviewed. Results These cases of primary extragonadal yolk sac tumor occurred with a median age of 4. 3 years and presented with variant symptoms depending on their anatomic location. The serum level of AFP had significantly increased. Microscopically,the tumor tissue was composed of proliferating tubules and solid sheets of tumor cells in a loose reticular stroma. Schiller-Duval bodies and eosinophilic bodies were present. Immunohistochemically,the tumor cells were positive for AFP,SALL4,CK,PLAP,and focally positivity for CD117,EMA,vimentin,p16,CD34,HPL,but negative for Oct3 /4,Sox-2,HCG,CD30,CA125 and WT-1. The labeling index of Ki-67 was from 1% to 90%. The prognosis was poor. Conclusions The histological features of primary extragonadal yolk sac tumor are similar to the ones originated from the gonad,but the former occurrs in infants mostly and has a poorer prognosis. The serum AFP level may be helpful to make the diagnosis of primary extragonadal yolk sac tumor.