B-Cell Prolymphocytic Leukemia

**Semantic type:** Neoplastic Process

**Definition:** A malignant B-cell lymphoproliferative process affecting the blood, bone marrow, and spleen. The B-prolymphocytes are medium-sized, round lymphoid cells with prominent nucleoli. The B-prolymphocytes must exceed 55% of lymphoid cells in the blood. Cases of transformed chronic lymphocytic leukemia (CLL) and CLL with increased prolymphocytes are excluded. The prognosis is poor. (WHO, 2001)

**Synonyms:** - B Prolymphocytic Leukemia - Prolymphocytic leukemia, B-cell type