The clinicopathologic analysis of yolk sac tumor in 16 cases

Objective:To investigate the clinicopathologic characteristics,immunohistochemistry staining and differential diagnosis of yolk sac tumor(YST) for providing the reference in the clinical diagnosis and treatment of YST.Methods:The pathologic characteristics in 16 YST cases diagnosed by operation and pathology were analyzed using HE staining and immunohistochemical technique.Results:Among 16 cases with YST,4 cases in testis,6 cases in ovary and 6 cases in extragonadal sites were found.Microscopically,the tumor cells arranging in loose reticular structure,Schiller-Duval bodies and hyaline droplets in the tumor tissue were detected.The positive expressions of cytokeratin and fetoprotein,human placental alkaline phosphatase and CD99,carcino-embryonic antigen and periodic ocid schiff in 16,8,1 and 12 cases were detected using immunohistochemistry,respectively.The expression of β-HCG in all cases were negative.Conclusions:YST is a rare disease,especially for happening in extragonadal sites.The clinical symptom of YST is not specific.The occurrence site,pathological features,immunohistochemistry and serum alpha-fetoprotein have important significance in the diagnosis and differential diagnosis of YST.