<prompt> 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?T- cell rich B - cell lymphoma with leukemic spill over in blood.Chronic lymphocytic leukemiaMantle cell lymphomaA definite diagnosis can not be made in this patient without lymph node biopsy  <response>: 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. 10cmprogressive lymphadenopathy Massive 6cmprogressive splenomegaly Progressive lymphocytosis doubling time 6 months Systemic symptoms; Weight loss 10in 6 months fever38deg C for 2 weeks extreme fatigue or night sweats Autoimmune cytopenias this may only require treatment of the autoimmune component not necessarily the leukaemia alignleft height155 width528CD 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. 