B-cell prolymphocytic leukaemia

§   Prolymphocytes >55% of lymphocytes in PB

§   Very rare

§   Occurs de novo or transformation of CLL

Clinical features

§   Elderly

§   Marked splenomegaly without peripheral lymphadenopathy

§   Rapidly rising lymphocyte count (usually >100)

§   Serum M-component in some

Blood/ Bone marrow

§   Double the size of small lymphocytes with prominent nucleoli

§   Diffuse intertrabecular infiltration

§   Pseudofollicles not seen

Immunophenotype

§   Strong expression of SIg M +/-D

§   B cell antigens

§   CD5 + in 1/3

§   CD23 negative

§   FMC7+

Cytogenetics

§        T(11;14) in 20%

§        Difficult to tell apart from blastoid variant of Mantle Cell

§        P53 mutations have been reported

Treatment

§   Responds to fludaribine and cladribine but less well than CLL does

§   CHOP

§   Splenic irradiation / splenectomy for symptomatic enlargement or cytopenias