[Three cases of primary lung and mediastinal malignant germ cell tumors --clinical and pathological studies].

This is a clinical and pathological study of malignant germ tumors in the lung or mediastinum. Germ cell tumors may be considered to originate from primitive germ cells with totipotency. One of 3 cases showed clinical and pathological findings suggesting that a part of the tumor differentiated into many kinds of tissue, such as growing and metastasizing. Initial diagnosis was performed radiographically and pathologically with difficulty. But finally, the first patient was diagnosed as malignant teratoma, the second as yolk sac tumor and the third as choriocarcinoma, in consideration of the tumor markers and clinical process.