[Comparative pathology and etiology of lymphatic tumors in fowl].

The tumours associated to lymphoid leucosis and Marek's disease are compared with lymphoproliferative diseases of man and other species, by morphological, immunomorphological, and aetiological criteria. Morphological and immunomorphological similarities were found to exist between lymphoid leucosis and malignant lymphomas of the B-cell system in man, more particularly, follicular lymphoma, lamphoblastic lymphosarcoma of the B-cell type, Burkitt's lymphoma, and immunoblastic lymphoma. Equivalent similarities with Marek's disease are relating particularly to Hodgkin's disease, infectious mononucleosis, and malignant lymphomas of the T-cell system. Aetiological relations were found to exist between lymphoid leucosis and the oncorna-virus-dependent lymphatic tumours in mammals, while similarities with Marek's disease were relating to infectious mononucleosis, Burkitt's lymphoma, and herpes-virus-dependent lymphatic tumours in monkey. Reference is made to the model nature of both lymphoid leucosis and Marek's disease and the resulting relevance to tumour research.