Differences in behavior and prognosis between leukemic and lymphomatous forms of a transplantable hamster lymphocytic neoplasm induced by simian virus 40.

A lymphocytic leukemia of probable monoclonal derivation, induced in a Syrian golden hamster by the oncogenic DNA simian virus 40, was adapted to grow in the allogeneic host either as leukemia or as lymphoma. The leukemia, which was produced by transplanting subcutaneously neoplastic lymphocytes that had circulated through and/or proliferated in lymph nodes and spleen, was characterized by dissemination with systemic manifestations and poor prognosis. The lymphoma, which was produced by transplanting subcutaneously neoplastic lymphocytes that had proliferated at subcutaneous sites of cell implantation, was characterized by localization and favorable prognosis. Evidence indicates that the tissue environment the neoplastic lymphocytes encounter during circulation and/or proliferation regulates their subsequent behavior in the intact host. Since the leukemic and lymphomatous forms of this animal model resemble very closely the analogous human lymphocytic neoplasms, it can serve as a means to elucidate the factors responsible for the differences in their behavior and to determine how these differences may influence prognosis and response to therapy.