A Cysticercus Carcino-Osteochondro-Sarcoma of the Rat Liver with Multiple Cysticercus Sarcomata

Abstract

It is remarkable that among more than 2,100 rats in our colony which from July 30, 1920, to April 12, 1928, developed cysticercus tumors of the liver following experimental infestation with Cysticercus fasciolaris , the larva of the cat tapeworm Taenia crassicollis , there was not a single carcinoma whose origin could in any way be attributed to the stimulation by the parasite. In a previous study (1) of cysticercus tumors of 1,400 rats (1) the writers found that all these tumors were of mesothelial origin and all except one were malignant. Two of the neoplasms contained hyaline cartilage and two contained both cartilage and osteoid tissue or bone. Of these four tumors one was an osteoid chondroma, one a chondrosarcoma, one an osteo-chondrosarcoma, and the other a mixed cell sarcoma containing islands of cartilage. Since the publication of this article we have encountered another Cysticercus chondroma or chondrosarcoma and the interesting mixed tumor which is the subject of this report. In addition to these, two rats developed benign cyst-adenomata which apparently originated in isolated bile ducts in the walls of Cysticercus cysts. Excluding the tumor which will be presented in this paper, these two adenomata were the only epithelial growths which have arisen in the walls of parasitic cysts among more than 2100 rats bearing Cysticercus tumors.