Immature teratoma of the ovary--an unusual case.

A 30-year-old female was found to have a malignant immature teratoma of the ovary 14 years ago. This was treated with surgery followed by chemotherapy. Two years later, hepatic metastasis was discovered and treated with different multiple-agent chemotherapy, resulting in transformation or evolution into a mature teratoma form of disease. Twelve years later, this disease underwent malignant degeneration and transformed into a metastatic adenocarcinoma. This case report illustrates that malignant ovarian immature teratoma, teratocarcinoma, like its testicular counterpart, can evolve or differentiate into an apparently benign form of disease, but ultimately leads to death due to subsequent malignant transformation into new forms of malignancy arising from any of the three primordial germ cell layers.