A neoplasm of prolymphocytes affecting the blood, bone marrow, and spleen. It is characterized by prolymphocytes exceeding 55% of the lymphoid cells in the blood and profound splenomegaly.

Synonyms: Prolymphocytic Leukemia, B-Cell Leukemia, B-Cell Prolymphocytic B-Cell Prolymphocytic Leukemia B-Cell Prolymphocytic Leukemias B Cell Prolymphocytic Leukemia Prolymphocytic Leukemias, B-Cell Leukemias, B-Cell Prolymphocytic Leukemia, Prolymphocytic, B-Cell