Primary lymphoreticuloses of the nervous system in animals

Lymphoreticular proliferative disorders occur in most species of animals including submammalian vertebrates but only occasionally affect the nervous system. Primary lymphoreticular disorders of the nervous system have been recognized in chickens as a herpesvirus-induced avian neurolymphomatosis and in mammals, patricularly in the dog, as reticulum cell sarcomas originating from perivascular mesenchymal precursor cells. Criteria have been discussed to distinguish neoplastic from inflammatory lymphoreticuloses but borderline cases exist where a clear distinction is not always possible.