抄録
A 14-year-old girl was found to have right ovarian tumor of 12×6×3cm, which is not associated with any apparent metastasis at her first laparotomy. Although right oophorectomy was performed successfully, tumors were found disseminated into the abdominal cavity 3 months later, accompanied with the increased serum alpha-feto protein(AFP)level. In spite of the vigorous chemotherapy using vincristine, actinomycin-D, and cyclophosphamide, tumor growth continued. Repeated tumor resections were performed to eliminate tumors. After the final resection serum AFP level decreased to normal and no tumor regrowth has been detected. Microscopic examination of the resected tumors demonstrated that the primary tumor was composed of the tridermal immature tissues containin some embryo id bodies. Metastatic tumors were mostly found as the peritoneal dissemination but a few lymph node metastases were also found. All metastatic tumors were also composed of mature and immature tissues of the tridermal origin, but they did not contain any tissue suggesting malignancy or embryoid bodies. Immunoperoxidase techniques revealed that AFP was located at the yolk sac tissue in the embryoid body, at the liver tissue-like cell clusters, and at the tubular structures of immature endodermal origin. Embryoid body may be the structure which suggests the presence of the totipotent cells, which can metastasize and differentiate into any embryonic or adult tissues. These totipotential cells may not necessarrily be of malignant nature. AFP can be found in the benign teratoma when it contains any tissne that can produce AFP in the course of fetal development.
