THE PATHOGENESIS OF TUMORS OF THE LIVER PRODUCED BY BUTTER YELLOW.

A conspicuous feature of the cirrhosis that is produced by butter yellow is the new formation of bile ducts that sprout from ducts of the larger portal spaces and penetrate between "portal units" to anastomose with liver cell columns at the periphery of these units. Hyperplasia of the liver may occur with butter yellow administration in the absence of cirrhosis or other change associated with widespread destruction of liver tissue; it occurs as diffuse or focal lesions and affects both parenchymal cells and newly formed ducts. Focal hyperplasia is a precursor of trabecular and adenomatous hepatomas which arise as multiple tumors. Butter yellow causes localized cystic dilatation of newly formed bile ducts unaccompanied by acute or chronic inflammation and liver cells adjacent to them may undergo hyperplasia. Cystic ducts by proliferation of their epithelium may form cyst-adenomas. Butter yellow causes newly formed ducts to undergo dilatation, and with acute inflammation and fibrosis to produce circumscribed macroscopically recognizable lesions (cholangiofibrosis). Cholangiofibrosis is the precursor of tumors that reproduce the histological characters of small bile ducts (cholangiomas), and often proceed to the formation of scirrhous carcinoma. Hepatomas, cyst-adenomas, and cholangiomas may become malignant with formation of metastases in which the characteristics of the parent tumor are reproduced.