A 48 year old woman was admitted with a history of weakness for two months. On examination, cervical lymph nodes were found enlarged and spleen was palpable 2 cm ptatelet count 237 X 109L and total leukocyte count 40 x coarse clumped chromatin. Bone marrow revelaed a nodular lymphoid infiltrate. The peripheral blood lymphoid were negative for CD 19. CD5, CD 20 and CD 23 and were negative for CD 79 B and FMC - 7. What is the most likely diagnosis?

Answer is B (Chronic Lymphocytic Leukemia) Coexpression of the B Lymphocyte lineage marker CD 19 and the T lymphocyte marker CD 5 is unique to CLL and Mantle cell Lymphoma. 10cm)/progressive lymphadenopathy * Massive (>6cm)/progressive splenomegaly * Progressive lymphocytosis (doubling time <6 months) * Systemic symptoms; * Weight loss >10%in 6 months fever>38deg C for >2 weeks extreme fatigue or night sweats * Autoimmune cytopenias (this may only require treatment of the autoimmune component not necessarily the leukaemia) " align="left" height="155" width="528">CD 23 is expressed by CLL and not by Mantle cell Lymphomas. CLL cells are also negative for CD 79B and FM 7 and hence CLL is the answer of choice. CDS CD9 CD23 Mantle cell Lymphoma ++ ++ +-/+ CLL ++ ++ ++ Mantle cell Lymphoma also tend to express higher levels of CD79a and CD79b than CLL.