Abstract
We presented four cases of pineal tumors with autopsy findings. Our pathohistological studies demonstrated that the tumor of cases 1 and 2 was of the two-cell pattern, case 3 was teratoma with foci of the two-cell pattern, and case 4 was a mixed tumor of immature teratoma, embryonal carcinoma, choriocarcinoma and two-cell pattern. Cases l and 2 were histologically similar to a part of the tumor of cases 3 and 4. The histological appearance of “pinealoma” had been discussed since 1923. In considering the results of our studies, we agree with the theory that the pineal tumor of the two cell pattern arises from the germ cells migrating into the pineal region. The so-called “pinealoma” has to be discussed in more detail from this point of view, and we wish to emphasize that the correct diagnosis of pineal tumor should be based on the examination of all the elements of the tumor.
