lymphosarcoma cell leukemia /-särkō″mə/ [L, lympha + Gk, sarx, flesh, oma, tumor] , a malignancy of blood-forming tissues characterized by many lymphosarcoma cells in the peripheral circulation that tend to infiltrate surrounding tissues. These cells are extremely immature and larger and more reticulated than lymphocytes. The disease may accompany lymphoma or exist as a separate entity with bone marrow involvement. Also called lymphoblastic lymphoma, lymphoblastic lymphosarcoma, lymphoblastoma.