The important rôle which chronic irritations play in the etiology of malign neoplasms has been proved by numerous clinical and experimental observations. The facts are too well known to be reviewed, and I will confine myself in the present paper to the reports which deal with the primary malign tumors of the liver and their relations to chronic alterations apparently preceding their development in this organ.
It is an interesting fact that in the liver, which possesses the greatest ability to regenerate, primary malignant tumors are rare. These consist of epithelial tumors derived from the liver cells or epithelial cells of the bile ducts, and mesenchymatous tumors originating either in the stroma or in the endothelium of the blood capillaries. The epithelial tumors are comparatively more frequent than the mesenchymatous ones.
CARCINOMA OF THE LIVER
In the statistics of necropsy material, primary carcinoma of the liver occurs in from 0.02