APPENDIX B 253
every normal human gestation developed a
conspicuous destroying and eroding tendency—that for the purpose of the
implantation of the egg it destroyed the decidua, and that processes of it
might extend almost through the thickness of the uterus. Between this normal
destruction and that of malignant chorio-epithelioma a completely closed chain
of cases could without difficulty be found, with gradual progression of
malignancy. Cases often arose where it was difficult for the pathologist to
determine whether he was dealing with a normal or an abnormal destruction.
If a parasite were postulated to account for
chorioepithelioma, its advocates would find difficulty in escaping from the
conclusion that such a parasite was not also required to stimulate the
implantation and development of the normal egg. He decided that malignant
chorioepithelioma only differed in degree from the normal processes. Certain
embryomata or teratomata were encountered in the sexual organs, ovaries and
testes. Occasionally these tumours were very malignant. They destroyed,
recurred, and formed metastases in distant organs. In recent years trophoblast
or chorion-cells had been found associated with these turnouts. This
trophoblastic tissue in its typical form was completely characteristic, and it
resembled in every morphological respect the trophoblast of normal gestation.
At times the cells formed solid epithelial strings and nests—there arose
ordinary carcinoma. In this connection he produced micro-photographs taken
from such a tumour of the testis. It consisted chiefly of nothing but trophoblastic
tissue, with here and there cartilage, skin, and tubes of columnar epithelium—a
picture which, he maintained, each of his hearers would recognize as the
trivial picture of a carcinoma or adenoma. He desired that day to add something
new which appeared to him to show that chorio-epithelioma was not limited to
the sexual organs, but that it might occur elsewhere. In itself that would not
be specially remarkable, because in